Automotive Wiring & Electrical Systems Volume 2 - Projects 9781613252666

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CarTech® CarTech®, Inc. 39966 Grand Avenue North Branch, MN 55056 Phone: 651-277-1200 or 800-551-4754 Fax: 651-277-1203 www.cartechbooks.com © 2015 by Tony Candela All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without prior permission from the Publisher. All text, photographs, and artwork are the property of the Author unless otherwise noted or credited. The information in this work is true and complete to the best of our knowledge. However, all information is presented without any guarantee on the part of the Author or Publisher, who also disclaim any liability incurred in connection with the use of the information and any implied warranties of merchantability or fitness for a particular purpose. Readers are responsible for taking suitable and appropriate safety measures when performing any of the operations or activities described in this work. All trademarks, trade names, model names and numbers, and other product designations referred to herein are the property of their respective owners and are used solely for identification purposes. This work is a publication of CarTech, Inc., and has not been licensed, approved, sponsored, or endorsed by any other person or entity. The Publisher is not associated with any product, service, or vendor mentioned in this book, and does not endorse the products or services of any vendor mentioned in this book. Edit by Paul Johnson Layout by Monica Seiberlich ISBN 978-1-61325-266-6 Item No. SA367 Library of Congress Cataloging-in-Publication Data Available Written, edited, and designed in the U.S.A. Title Page: The MSD ignition module is wired together on the bench, and there is plenty of room around the ignition components and good room for the wiring behind them. Behind the ignition module are relays for the door poppers, power windows, air conditioning, and the starter solenoid. Back Cover Photos Top Left: Use your DMM to locate the dimmer output of the headlight switch; it is active with the parking lights and varies in voltage when rotating the dimmer. Piercing probes are very handy for this and they leave only a tiny hole in the insulation of the wire. Top Right: A high-amp alternator is a must for many high-performance vehicles that draw a lot of current. Bottom Left: A car with many high-amp equipment and accessories requires batteries and cables capable of supporting the system. The circuit breakers protect the wing. Bottom Right: The interior light module is completed. I cleaned this area with isopropyl alcohol and used high-quality double-stick tape to mount it.

CONTENTS INTRODUCTION CHAPTER 1: ADDING A BASIC CIRCUIT TO ANY HOT ROD CHAPTER 2: PERFORMANCE LIGHTING CHAPTER 3: PERFORMANCE GAUGES CHAPTER 4: ELECTRIC FANS CHAPTER 5: HIGH-PERFORMANCE CHARGING SYSTEMS CHAPTER 6: AFTERMARKET WIRING HARNESS SOURCE GUIDE

ACKNOWLEDGMENTS I’d like to thank a few people who continue to influence me. As in my previous books, my first thanks are to my parents for teaching me that I can do anything I choose to do if I just apply myself! In addition, I thank Steve Meade, Todd Ramsey, Jason Digos, Motor Mike, Bill Surin, and Garry Springgay for continually making me look at things with a fresh perspective. A book of this nature simply wouldn’t be possible without a bunch of assistance. I thank the numerous people who allowed me to use their prized possessions in the examples; they are Chris Downs, Pete Horton, Bill Surin, Mike Cote, and Motor Mike. I also thank the following companies that have bent over backward to help me in this venture: Fluke, Mitchell 1, MSD Ignition, Holley, Auto Meter, Painless Performance Products, ISIS Power Products, Iraggi Alternator, Mr. Gasket Company, XS Power, MagnaFuel, and Beck Racing Engines. Finally, I thank a few people specifically for making themselves readily available to me: Anthony D’Amore, Jim Candela, Frank Beck of Beck Racing Engines, Todd Ryden of MSD, and Doug Flynn of Holley. Thank you!

INTRODUCTION Thank you for picking up my second foray into the topic of automotive wiring. This book is designed to give you clear and concise step-by-step directions for completing the most common electrical projects of a performance nature. Here, you will find information that is presented in real-world terms that you easily understand: quite the contrast from the typical installation manual that you don’t read anyway. Heck, we don’t need no stinkin’ manual. I think you’ll really enjoy this book because, quite simply, it picks up where the installation manual leaves off. Admittedly, some excellent installation manuals are included with aftermarket products, such as those included with MSD ignition products. But they stick to a fairly straight path. This book presents a lot of “what if” scenarios and provides the answers. I’ve included every photo and diagram that I think you’ll find necessary to get you to the Promised Land. In addition, if I use a specific tool or part, I give you the information that you need to obtain it. Remember, the objective of any project is to complete the work correctly the first time.

Does this look familiar? It is an example of the “just get it done” attitude, and it is all too common with enthusiasts’ prized possessions. Can you imagine how difficult this is to service? Are all circuit protected properly? Sometimes, it can be difficult even to begin fixing a problem like this. After all, where do you start? The best recipe is to avoid it altogether. The projects in this book are laid out in such a way that the first ones are the easiest to comprehend and complete, and the later ones are the most difficult. Trust me, I’m a seasoned professional with more than 25 years of experience in this field, and the 1941 Willys in Chapter 6 threw me a couple of curve balls! But have no fear, I show you the solution to every challenge I encountered. I’m confident that you’ll find something between these covers that has been on your “to do list.” I’m also confident that you’ll find something here to add to your list. If you’ve read my first book, Automotive Wiring and Electrical Systems (CarTech SA160), you can look at this book as Part 2. Maybe you own the first book, or maybe you just borrowed your buddy’s copy. If you haven’t read it, that’s okay, too. If you find that the content of this book assumes that you know the basics, you are correct. If you’re a little rusty when it comes to making solid electrical connections, using a digital multimeter, or being sure of the difference between SPST and SPDT relays, you may choose to pick up a copy of Automotive Wiring and Electrical Systems. (I may from time to time refer to specific chapters or pages of Automotive Wiring and Electrical Systems for additional

information that pertains specifically to the projects featured in this book.) I’m confident that you’ll find the information in this book easy to digest, informative, and valuable. I’m fortunate to have so many friends with hot rods, and many of them are featured here. All of the work shown was done in either my garage or one of theirs. Although I spent years working in the best installation facilities (and still have a few of them available to me), this is proof to you that you can easily do these projects in your garage, under your carport, or in your driveway. Before we get our hands dirty, I’ll share a story with you that I think you’ll relate to. Shortly after Automotive Wiring and Electrical Systems went to print, a friend of a friend contacted me about his Mustang, a 1967 Shelby “Eleanor” clone. Chris, the owner, complained to me that he had some electrical problems that he needed help sorting out. I scheduled time to meet him to see if I could offer some assistance. When I arrived, I was blown away by the yellow-and-black paint scheme of this car. It had the right wheels, the right stance, and the right engine: a healthy 347 stroker engine that made about 450 hp. What a gorgeous car; I’d park this steed in my stable any day! As we talked, I realized that he had owned this vehicle for nearly four years but hadn’t driven it even 200 miles in that time. Why? Simple. He was scared to death that the electrical gremlins in the car would strand him or, worse yet, cause an electrical fire. A friend of his had recently had his project car catch fire in his garage, and it burned his house to the ground. As I looked the vehicle over, I realized that it was not very different from many that I see at local gatherings. Specifically, numerous aftermarket accessories had been added to a completely stock electrical system. Sure, this car had a brand-new reproduction wiring harness in it, but it still had similar current-carrying capabilities as the original wiring harness. After all, it was designed to replace an old, worn-out, hacked-up one and power the exact same stock Ford accessories installed in the car. This vehicle was fitted with these aftermarket electronics:      

MSD 6AL ignition system. 7 amps maximum; no worries here 18-inch electric fan 2 pairs of PIAA fog lights. Remember, this is an “Eleanor” clone Auto Meter gauges. No worries; current draw is on par with the factory gauges Kenwood AM/FM/CD player. No worries; current draw is minimal Aftermarket A/C. The repro harness addressed this, so no worries

Chris was really concerned; when he parked the car overnight, the battery would be totally dead in the morning. Try as he did, he was unable to determine the source of this problem. He had several friends try to help him solve this problem. After four years, and having the dash out of the car numerous times to no avail (a real pain in the neck!), he felt it was time to resolve these issues so he could begin enjoying this car. I agreed to help, and he dropped the vehicle off at my house for a week. The first thing I did was measure the current draw on the battery with the ignition off and both doors closed. I recorded more than 3 amps; that’s a bunch. Yep, time to remove the negative cable so that I don’t run the brand-new battery flat; he had just purchased it the day before. When I dig into a problem like this, I typically don’t look for the problem. Huh? Let me explain. Based on what Chris told me, I felt there were numerous minor problems to be uncovered, and boy, was I right. You see, Chris had given me enough information to determine that there could have been problems that he wasn’t even aware of; the first hint was the fact that numerous people had attempted to help him resolve the current-draw problem. There could be no telling what I would find. Sure, he had a list of things that didn’t work or didn’t work properly that he wanted fixed, but none of them was in any way tied to the major problems. Those would be the current draw and the source of power for that current-hungry 18-inch electric fan. Time to get to work.

This is how a completed wiring project should turn out. Note the vast amount of electronics in the tin of the 1967 Nova street/strip vehicle (profiled in Chapter 5). Careful planning went into this project. Each circuit and relay has the appropriate protection, and all of the wiring is laid out with an eye toward serviceability. After two days of fixing smaller problems, and I found many, it was time to dig into the current-draw problem. I had the car totally apart and had access to the complete wiring harness, so I was able to quickly determine the root of the problem. After I’d unplugged every fuse in the fuse panel, disconnected the Kenwood stereo, and disconnected the ignition box, I still had the same current draw. A quick look under the hood, and I was staring directly at the external voltage regulator for the alternator. I had it unplugged in seconds, and the current draw dropped to about .5 amp. As I probed the regulator harness with my digital multimeter, I noticed that the “I” terminal (ignition) had 12 volts on it with the key off. This caused the magnetic field of the rotor to be energized, which was the source of most of the current draw. It took me a little while longer to determine that the ignition switch was wired incorrectly, causing the problem. The same circuit that powered the regulator was also the source of power for the gauge cluster. When I addressed the problem, the current draw dropped to zero; as in, not even a milliamp. Now, let’s look at this from a little different perspective. If I would have attacked this problem the way most people do, I would have likely found the current draw from the regulator. I could have then assumed that the wiring harness was wired incorrectly, cut the wire to the regulator, and run a new one to the ignition. After all, current draw would have been reduced to about .5 amp. And the electric fan worked, so why mess with it? This is absolutely not the way to tackle such a problem. And that fan? Well, further investigation revealed that its 14-gauge power wire (too small) was spliced into the 18-gauge wire from the ignition switch (unfused) to the MSD ignition. This splice was behind the main A/C vent assembly and extremely difficult to access. It was soldered, but the connection had seen so much heat through it that it had melted about 2 inches of insulation in every direction away from the connection. This confirmed Chris’ worst fear; a fire was a definite possibility. Rest assured, I fixed this, and all of the other problems on his list, the correct way. Two months after Chris got his car back from me, I saw it parked at a local car show. He was so excited to be driving and enjoying it. He exclaimed, “I haven’t driven it in two weeks, got in it this morning, and it started right up. And everything still works!” Each of the projects in this book can be approached in the right way or in the wrong way. I show you how to tackle each one in the correct way, in a way that I think you’ll easily grasp. The result is that you’ll be able to avoid the heartache Chris endured and enjoy your vehicle.

This 1967 Mustang is one sweet ride, and it draws a crowd everywhere it goes. For four years after it was built, the owner wrestled with electrical gremlins of all kinds and was scared to drive it. Now that the electrical is solid, the owner can enjoy the car without fear of it not starting the next morning.

CHAPTER 1 ADDING A BASIC CIRCUIT TO ANY HOT ROD Before beginning, I should note that this book makes the assumption that the vehicle you own has a 12-volt negative-ground charging system. That is, the vehicle is equipped with a 12-volt battery, and its negative terminal is connected to the vehicle chassis. If you own a vehicle with a 6-volt or even a positive-ground charging system, the theory still applies, but the specifics do not. Safety First Generally speaking, an automobile presents a number of challenges when a person is working on or adding to the electrical system. Very high currents are possible in a 12-volt system; short circuits can be very dangerous and can quickly cause fires. In addition, accessing or routing wiring in many areas requires you to contort your body into the weirdest of positions. You need more than a basic understanding of and respect for the complexity of the electrical systems in today’s vehicles to work on them competently. When in doubt, seek the advice of a professional, even if it means paying that person to do the work. Making simple mistakes can have serious consequences. Hazards Presented by On-Board Computers Modern vehicles have many luxuries that we now take for granted, including fuel injection, a fully electronic automatic transmission, an antilock brake system (ABS), variable valve timing, a supplemental restraint system (SRS), and many more. Each of these requires lots of decision-making power, power found in an on-board computer. Working on vehicles with on-board computers requires specialized tools. I strongly discourage the use of a standard incandescent test light on any vehicle with an on-board computer. I also discourage connecting 12 volts or ground to any wire that you’re not 100 percent sure what it’s connected to. I certainly wouldn’t do this in modern vehicles. Even the radio harness in today’s vehicles can include numerous connections to on-board computers, such as the vehicle speed sensing (VSS) circuit or a data connection to a vehicle locator, as examples. Don’t be a cowboy here. Only make connections to wiring you’ve verified. Finally, many of the connections between computers in the modern vehicle are of a new variety. Different BUS systems (such as CAN bus and MOST bus) are used in some vehicles, and the information transmitted on them is digital. Fiber-optic cables may also be used to pass information digitally between components. Again, if in doubt, I recommend that you contact a professional. It’s less expensive to swallow your pride than to pay for a costly mistake. Disconnecting the Battery: When? When working on or servicing automotive batteries, always wear eye protection. Many automotive batteries have sulfuric acid within them, which is extremely caustic and can cause irreversible damage. When working on or servicing automotive batteries, remove jewelry, such as rings and watches, as they are great conductors. Should they accidentally come between the positive battery post or terminal and the vehicle chassis, they could cause a short circuit. This results in extremely high current flowing through them, and the resulting heat can cause severe burns to fingers, hand, or wrist.

Never work on or around an automotive battery with a lit cigarette! In addition, keep open flames away from the battery, as they can cause a lead acid battery to explode! I’ve always been perplexed when the first line in the instructions of any aftermarket product begins with “Step 1: Disconnect the Battery.” In many cases, this isn’t necessary or advisable. Now, I’m not condoning that you do not follow the manufacturer’s instructions, but you should understand when to disconnect the battery and when not to. Quite simply, you’re disconnecting the battery to eliminate the risk of damaging the vehicle’s electrical system when working on the vehicle; sound judgment, indeed. I recommend disconnecting the battery when you are:  Making major changes or additions to the electrical system.  Making extensive changes to the vehicle’s drivetrain, exhaust, or suspension components.  Working around a battery in tight quarters; the end of a wrench or ratchet between the positive battery terminal and the chassis is a good way to get in trouble fast!  Unplugging a module or computer for any reason.  Disconnecting any large power wires from anything, such as alternator, starter, fuse box, ignition switch, etc., as these are typically tied right to the battery.  Welding to the chassis, frame, or body.  Drilling holes through the firewall; a drill bit can quickly pierce a harness as it breaks through and short it to ground! The above are simply common sense. Chapter 1 of Automotive Wiring and Electrical Systems includes more information on safety. Even the correct way to disconnect and reconnect a battery is outlined. It is important to practice safety every time you embark on a project in a vehicle. Now that I’ve gotten that out of the way, it’s time to dig into the projects. Let’s begin with a simple one. Project 1: Installing Interior Lighting Maybe you built your hot rod from scratch. Maybe your weekend cruiser was a quarter-mile warrior at one time in its life. Regardless, I see plenty of cars at local gatherings that lack one simple luxury: interior lighting when the door is opened. Believe it or not, this project has been on my personal to-do list far too long. My Olds served part of its life as a 1/8-mile bracket car before I purchased it. When it was built, the previous owners stripped the entire stock electrical system out of it. Their handiwork in rewiring the vehicle for track use was the foundation for Automotive Wiring and Electrical Systems. When I rewired the car, I never got around to installing any interior lighting. I always figured I would do that when I redid the interior, something that is still on my to-do list! For as long as I’ve been driving the car, the lack of interior lighting has been a real inconvenience. A month went by, then it was July, then four years passed. I’m sure you know exactly what I’m talking about.

My 1972 Oldsmobile Cutlass S is all 1980s Pro Street. So far, I’ve logged more than 8,000 street miles on it, and it’s a blast! This vehicle is the subject of numerous projects in this book.

I needed a solution that would provide this convenience, yet not interfere with my future interior plans. Basically, I didn’t want to go through the effort of installing something that I would be removing when I did get to the interior work. After a bit of research, I found a simple kit from Painless Performance Products that perfectly suited my needs. It’s universal, so it suits many applications. In addition, I purchased a pair of OEM-type pin switches from OPGI, as the doorjambs in my Olds were already drilled and tapped for pin switches (OPGI sells only the dual-terminal switches). You need the following parts: Schematics Electronic circuits are typically represented in wiring diagrams called schematics. A schematic is a simplified drawing of a circuit, and it uses symbols to represent the individual components of the circuit. Reading a schematic is simple, but most do not have a key, as the symbols have been standardized. This is a key to the most commonly used symbols in automotive schematics and for the schematics provided in this book.

Shown here are all of the parts required for the installation of interior lighting in the Olds. This project is an extremely simple one that anyone can do in a few hours.  

Painless Performance Products Courtesy Light Kit (PN 30702) pin switches: AC Delco (PN D6063), GM (PN 25603977), or OPGI (PN NZ00016)

In addition, you need the typical electrical tools and a roll of 3M Scotch Super 33+ electrical tape; this is the only electrical tape I recommend. Use it once, and you’ll know why. This installation is really quite simple. Refer to Figure 1.1 for circuit specifics. The interior light circuit in most vehicles switches ground to activate the lights, just like this one does. In some vehicles, Fords for example, this circuit switches positive to activate the lights. If you’re adding this to a vehicle that doesn’t have interior lighting at all, you can wire it exactly as this example shows, regardless of the make of vehicle or how the original system functioned.

The Painless Courtesy Light Kit includes a pair of universal pin switches and the associated bullet connectors; the kit can be used in any vehicle. But, if your doorjambs already have stock pin switch locations (just empty), as the Olds jambs had, purchase the factory-type switch for a perfect fit.

Figure 1.1. Prepare light harnesses for installation.

Before getting into the car, prep any harnesses by grouping wires with electrical tape to make the installation neat and orderly. This minimizes the amount of work to be done under the dash of the vehicle. Tape the harnesses about 12 inches from each light to make a service loop in the vehicle. A service loop allows you to easily remove the light should you ever need to work around it because it’s in the way. Run wiring between the pin switches.

I used white wire in this step because this is the color that GM used for many years for the dome lamp trigger lead (in GM vehicles, white is the trigger, and orange is the power), but you are free to use black to stay consistent with the Painless wiring. The lights are not polarity sensitive, so it really doesn’t make a difference. Mount interior light on driver’s side.

The courtesy light mounts neatly under the dash and out of the way. All that is required to mount it is to drill a single hole and screw it into place. Look closely at the hole to the left where all the ground wires come through. Although the factory light is long gone in this vehicle, the underdash light snapped into place in the two flat openings.

Route wiring from light to pin switch.

Run wiring from the driver-side light to the pin switch. The black wire is the trigger lead from the driver-side courtesy light. It connects to the wire that runs between the switches and to the pin switch. Connect female push-on terminal to wires.

After crimping the .187-inch female push-on connectors onto the wires, create another service loop by taping the wires as shown. You should always leave yourself enough length to remove switches for whatever reason, and doorjamb pin switches are no exception.

Connect driver-side pin switch.

Some factory-type GM pin switches may have two terminals; others may have one terminal. The dualterminal switch (shown) was originally used only on the driver’s side. Originally, it had one terminal connected to the dome light trigger, and the other one connected to the ignition switch to activate the key buzzer when the driver’s door was opened with the key in the ignition. You only need one terminal for this circuit. Install driver-side pin switch.

Shown here is the completed installation of the driver-side pin switch. It’s a perfect fit to the original threads.

Add pigtail to install other interior lights. At some point down the road, when the interior finally does get finished, I plan to have a center console. I envision adding some door-triggered lighting to it. In addition, I may also add a traditional overhead dome lamp. By thinking ahead and adding a pigtail now, connecting additional interior lighting will be very easy when the time comes.

The white wire from the courtesy light is on the right. The wire that runs from the driver’s pin switch to the passenger’s pin switch is on the left. Because the length of wire from the courtesy light was too short to reach the fuse panel, I extended it with orange 18-AWG wiring, just like the original GM circuits. This made an excellent place to add a pigtail for interior lighting additions. Solder both connections.

Shown here is the pigtail. Terminate it with push-on connectors so that adding lighting at a later time is a snap. Repeat Steps 3 through 7 for the passenger’s side. Connect power input leads.

The leads must be attached to a constant source of power. The fuse panel on the left is a Painless 12circuit universal panel (PN 30001). Note the Dome LT SW connection point. This is the perfect place to source power for this circuit. This required that a 16-14-AWG no. 10 fork terminal be crimped to the power wiring for the lights to make this connection. If your fuse panel doesn’t have such a convenient location, connect this to a fused source of constant power.

The Painless 12-circuit universal panel is all powered up, and the convenience light circuit is ready to test. Test circuit.

Open either door, and the lights come on. It’s simple. All in all, this project was very simple. Again, I like the fact that all of the components are unobtrusive and will not in any way affect future interior work. Additional Functionality The best thing about doing a project like this is that you can customize its operation to suit your application or desire. As shown, the interior lights only come on when either door is opened. You may also add a way to make them come on manually. As the Olds does not have a traditional headlight switch (parking lights and headlights are controlled via a Painless switch panel), I did not wire the interior lighting into it. Most OEM and aftermarket headlight switches are designed so that, if you rotate the switch fully in one direction, you can manually turn on the interior lights. Refer to Figure 1.2 for the specifics on adding this feature.

Figure 1.2.

Figure 1.3. If your vehicle serves double duty as a street and strip car, and you’d like a simple way to manually disable the interior lighting, you can add a simple SPST switch in line on the power input lead to the lights. This setup allows you to work on the vehicle in the pits with either or both doors open without worry of draining the battery. Refer to Figure 1.3 for the specifics on adding this switch. In the case of the Olds, the Painless fuse panel has a fuse for the dome lamps (and hazard lights). If I need to disable the interior lighting for any reason, it’s a snap to remove the fuse. Project 2: Adding Turn Signal and High-Beam Indicators Okay, I admit it. Sometimes I’m too busy listening to the blower whine while cruising down the highway to notice that I’ve had my left turn signal on for 10 miles. My friend Jackie used to refer to this activity as “driving around the world to the left.” Really, it’s hard to look cool when you do this, and I’ve done it more often than I’d like to admit. Another problem is being oblivious to the fact that you have your high beams on. This oversight is a real annoyance to oncoming drivers.

Figure 1.4.

The solution to both is dash-mounted indicators. Obviously, if your vehicle has the stock dash, it likely also has stock indicators. But, if you drive a car that you built from scratch or a hot rod with a non-stock dash (as I do), this project is for you. I originally outlined a very basic version of this circuit in Automotive Wiring and Electrical Systems (on page 65). Let’s put the circuit to work for us to add this functionality. Refer to Figure 1.4 for the specifics. You need these parts:     

(2) 276-080 panel-mount LED holders (two per pack) (2) 276-304 5-mm green LED (two per pack) (1) 276-0311 5-mm blue LED (1) 271-1111 220Ω half-watt resistor (five per pack) (1) 271-1113 330Ω half-watt resistor (five per pack)

At the time of this writing, all of the listed parts could be purchased for around $12, so this upgrade is an incredibly inexpensive project. If you don’t have the exact values on hand, but do have some resistors, you may actually have exactly what you need. See sidebar “Using Resistors” on page 23 for an in-depth explanation.

This project requires a short list of parts, and these are all readily available at your local RadioShack. Let’s tackle the high-beam indicator circuit first. The blue LED has the following specifications:  

Operating voltage: 5 volts Current at operating voltage: 30 mA

For a running vehicle, I like to use 15 volts as a starting point and go down from there. That way, I don’t risk damaging the LED if the regulator ramps voltage up to 14.8, as I would if I used 14.4 volts as my starting point. Before proceeding, consider that the resistor and LED make up a simple series circuit. To provide the LED the voltage it needs (and no more), a 10-volt drop across the resistor is required. Recall that current is the same across all components in a series circuit, so in this case, that’s 30 mA. Using Ohm’s law, the math is as follows: R=E÷I Where:

R = Resistance in ohms E = Voltage in volts I = Current in milliamps (mA) R = 10 volts ÷ 30 mA R = 333.33Ω (Note: These specifications change from time to time with RadioShack parts; be sure to use the specifications printed on the package when calculating.) Using Resistors Resistors convert electrical energy into thermal energy. As that implies, they can become warm or even hot in normal use. Resistors go hand in hand with LEDs (light-emitting diodes). LEDs only require a few volts across them to illuminate. If there are more than a few volts, the LEDs very quickly burn out. Apply 12 volts to one LED, and it instantly fails. In addition, they require very little current. Look at the package that the LED comes in before tearing it open; the printed specifications include both the voltage rating and the current at that voltage. This is very important! The proper-size resistor limits the amount of current that flows through the LED by creating a voltage drop across the resistor itself. (The resistor and LED make up a simple series circuit.) Fortunately, it’s as simple as using Ohm’s Law to determine the correct value. So, what if (after you’ve done the math) you don’t have the exact value of resistor that you determined you need? Don’t worry; this is actually quite common. Although Project 2 in this chapter calls for 330Ω (ohm) resistors, I actually was out of them when I built the circuit. No problem; I did have 680Ω resistors on hand, and two of them in parallel is 340Ω, which is close enough. You can use any of the following formulas to compute the exact value of numerous resistors wired together, either in series or in parallel. In all of the formulas, the following apply: R = Resistance in ohms RT = Total resistance RN = The nth resistor Resistors in Series RT R1 + R2 + R3 . . . +RN This is the simplest formula. You get the total resistance simply by adding the values of all resistors wired in series. For example, a 100Ω resistor wired in series with a 1kΩ resistor has a total resistance of 1.1kΩ. Resistors of the Same Value in Parallel RT = R (value of one of the resistors) ÷ # of resistors This is also simple. Three 3.3kΩ resistors wired in parallel is 1.1kW (3300Ω ÷ 3). Resistors of Different Values in Parallel This formula is somewhat complex. It covers any number of resistors wired in parallel (even two): RT = 1 ÷ (1/R1 + 1/R2 + 1/R3 . . . + 1/RN)

Sometimes, it’s nice to prove a theory. I made the computation by using the formula shown in the sidebar “Using Resistors” above, and then I verified it with my Fluke 88 DMM. 330Ω is a standard value, and the part this project calls for. But, as I mention in the sidebar “Using Resistors” above, I was out of them when I built this project, so I used two 680Ω resistors in parallel instead. Insert LED into LED holder. Connect 6-inch wire to long terminal lead.

Secure a 6-inch piece of 18-AWG colored wire to the long terminal (its positive) of the LED. Tin the wire with solder. Then bend the ends of the LED and wire in a “U” shape with needle-nose pliers. Hook the LED and wire together and squeeze the Us closed. Solder wire to the LED terminal.

Be careful when applying heat to LEDs during the soldering process, as they are somewhat fragile.

Insulate connection with heat-shrink tubing. Repeat Steps 2 and 3 and solder 24 inches of wire to the short terminal lead.

Solder a 24-inch length of 18-AWG black wire to the short terminal of the LED. The RadioShack Helping Hands tool is quite handy when working with small parts like this. Solder 330Ω resistor to colored wires.

Solder one end of a 330Ω resistor to the end of the 6-inch piece of colored wire, and solder the other end of the resistor to a 36-inch length of the same 18-AWG colored wire. You should always make a practice of insulating components, such as resistors and diodes, when using them in projects like this. Simply strip short lengths of insulation from some 18-AWG primary cable, and slide them over the leads. Insulate connections with heat-shrink tubing.

Cover soldered connections with heat-shrink insulation to protect them from accidental shorts.

The completed high-beam indicator circuit should look something like this, ready to be installed in the vehicle. Now that the high-beam indicator circuit is done, it’s time to tackle the turn signal indicators. The math is a bit different here, as the LEDs have different specifications:  

Operating voltage: 2.1 V Current at operating voltage: 30 mA

Starting again with 15 volts, we need to create a 12.9-volt drop across the resistor. Using Ohm’s law, the math is as follows: R=E÷I R = 12.9 V ÷ 30 mA R = 430Ω The process is identical to the one used to construct the high-beam indicator circuit, except the installation of the resistors is different. In this case, I will be using two 220Ω resistors in series to get the proper value.

Hook the leads together end to end, and hold the assembly tightly while soldering the connections. The insulation over the resistors’ leads makes this circuit appear very neat. Next, heat shrink these connections to insulate them. Install LEDs in dash. Now that each of the indicators is wired, it’s time to install them. In the Olds, this required drilling three holes in the dash between the speedometer and tachometer and above the shift light and low oil pressure warning light. Measure twice and drill once so that you get your holes straight. This is an “after the fact” installation in my Olds, as the dash has already been mounted in the vehicle. Once I determined the correct location to drill the holes, I used a spring-loaded center punch to center the drill bit and keep it from walking during the drilling process. I also used an 18-inch-long aircraft-style drill bit so that I could avoid removing the steering wheel in the drilling process.

Drill a 5/16-inch-diameter hole for each of the LED holders in the dash panel. As LEDs can have somewhat directional light output, locate them so that they are within direct line of sight. I removed the low oil pressure Pro-Lite, shift light, and speedometer to better access this area.

Looks like my tenacity in determining the exact locations for the mounting holes paid off in spades. These panel-mount LED holders look really nice installed, and they are unobtrusive. Route harnesses.

Carefully bundle the harnesses together, and tie them securely. An unintended yank on the other end of the harnesses could rip the leads right out of the resistors, so you want to secure the harnesses well. Ground harnesses for each circuit.

Crimp a 16-14-AWG ring terminal onto the three ground wires. I used a 1/4-inch ring, but you should use the correct-diameter ring terminal to fit your need. Ground this to the dash structure, being sure to scrape the paint and use a star washer for maximum long-term conductivity. Connect high-beam indicator circuit to switch. Use your digital multimeter to determine which of the wires on the low/high-beam switch is the highbeam output. The high-beam output shows 12 VDC only when the high beams are on. Note that in the photo below, I only measured 10.87 VDC; this indicates a problem, specifically a bunch of voltage drop in the headlight circuit. See sidebar “Discovering a Problem” on page 30 for more details.

Once you’ve connected the high-beam indicator circuit to the low/high- beam switch, set your digital multimeter to determine the high-beam output of the low/high-beam switch. The 10.87 VDC reading is an indication that the headlight circuit in my Olds is not working optimally.

Connect turn signal indicators to turn signal switch.

Locate the turn signal switch harness on the steering column. Use your digital multimeter to identify the wires that go to the front turn signals. Solder and tape the corresponding indicator circuit to each of the left and right front turn signal outputs. If in doubt, obtain a wiring diagram of this switch. As shown here, light blue and dark blue are the correct colors on older GM vehicles. Discovering a Problem Sometimes, during a project like Project 2 in this chapter, you discover a problem that you need to resolve before proceeding. As the battery in the Olds rests at 12.6 VDC, I know I have a 1.73-volt drop at the high-beam output of the low/high-beam switch; this is not desirable, and, as a result, the headlights work less than optimally. This kind of problem is to be expected when you work on a 40year-old vehicle with extensive wiring modifications. In the Olds, the original builders did not resolve this issue, so it’s time to fix it now. After pulling the low/high-beam switch loose, I noticed a few things that were disconcerting. One was that the butt connectors used to connect the switch to the aftermarket wiring got quite warm with the high beams on. Although they pass the standard “pull test,” the heat is an indication of resistance. The second problem was the overall condition of the plug for the low/high-beam switch. The best way to resolve such a problem is with accurate data. Connect DMM across the low/high-beam switch. That’s right; you want to measure the voltage lost through the switch itself. This is commonly referred to as a voltage drop test. Connect the red probe to the input of the switch and the black probe to the high-beam output of the switch. In the case of this vehicle, these are non-standard colors.

The .50 VDC (shown here) is a bunch of voltage drop across a single switch. Yet, it still leaves almost 1.25 VDC of drop to be found somewhere else. For now, let’s address the voltage drop across the switch. I removed the plug from the low/high-beam switch, because all of the contacts were in need of replacement.

I removed the plug from the vehicle. After closely examining the contacts, I chose not to reuse this plug. I cut the plug from the mounting base for the low/high-beam switch, because I want to mount the switch back in the vehicle with the plastic base between the switch and floor. Repair the problem. It’s obvious that my Olds isn’t numbers-matching or even original in the slightest bit. So, I’m okay with totally modifying the connection to the low/high-beam switch itself in an effort to reduce the voltage drop through it. I crimped on 16-14-AWG female push-on connectors; these are the kind that really bite into the male terminals.

When using female push-on connectors to make solid electrical connections to the mating male terminals, such as those GM used on the low/high-beam switch shown here, always use the type that has curved contact points, such as the two on the right. These get a much better bite on the male terminals than the flat-style connectors pictured on the left. Then, I squeezed them closed very tightly with a pair of pliers so that when I slide them on the terminals to the switch they get a very good bite. Finally, I insulated them with heat-shrink tubing to protect the insulation. Obviously, the headlight circuit in the Olds needs more work to be optimized. (See Chapter 2 for an in-depth look at the entire process.)

The net result? How about a .07-VDC drop across the switch? That’s much better, and quite in line with what you would expect across such a switch. Even though this switch is nearly 40 years old, it has held up very well, thanks to its sealed design. These need to be connected to the front turn signals and not the rear signals. In many vehicles, the rear turn signals are powered up when the brake pedal is depressed. At this point, the installation should be complete and ready to test. Don’t tie up any of the wiring until after you’ve tested it for proper operation. Again, I think you’ll agree that this is another simple project. If you’ve glanced ahead in the book and looked at some of the more complex projects, you need to complete a few of the simple projects before attempting one of the more advanced projects. But, what if your vehicle is already equipped with interior lighting and indicators for the turn signals and high beams? No problem; the LED circuit illustrated here can be used to indicate that anything is powered up—from a line lock to a water/methanol injection system. I used blue and green LEDs for this project, but many different colors are available. Use your imagination and build one!

CHAPTER 2 PERFORMANCE LIGHTING Everywhere you look, many people are no longer happy with the stock lighting equipment on their cars. Many new technologies are currently available in nearly all areas of life. For example, many cities are upgrading age-old street lamps with cutting-edge LED lights. At the time of this writing, many higher-end automobiles offer HID (high-intensity discharge) headlights as standard fare. LED lighting is also gaining in popularity, but typically only in the aftermarket for off-road applications. So, why should you settle for low-performance lighting in your vehicles when you can improve it easily and substantially? This chapter addresses two ways to improve the performance and effectiveness of your headlights: servicing the existing headlight system and upgrading the stock headlights to higher-power units. Project 3: Servicing the Existing Headlight System Obviously, headlights require power continuously when they are on. Continuous loads, such as headlights and cooling fans, place large demands on the switches and wiring that power them. Over time, these demands can take their toll on the headlight switch, low/high-beam switch, and the wiring harness itself.

Looks like an ordinary 13-second Olds Cutlass, right? Wrong. This Olds packs more than 600 hp and runs in the 10s in the quarter. The wiring in this vehicle is quite common of what many enthusiasts end up with after numerous aftermarket upgrades. This project shows you how to do it the correct way. Classic vehicles, even if well cared for and with relatively low mileage, typically have a fair bit of wear on the electrical components of the headlight system, simply from use. Remember, an incandescent light bulb is really just a short circuit inside a vacuum, so it requires substantially more current to turn it on than it does to keep it lit.

For an instant, the high-beam filament of this halogen headlight requires a bit more than 4.5 amps of current at 14.4 VDC (representative of a running vehicle). This is its “inrush” current requirement. Consider that many older vehicles have four high-beam headlights and the stock wiring to them is typically 18 AWG. The contacts in the switches can be worn, pitted, or covered with carbon over time from the inrush of current required during each power-up of the headlights. In addition, the electrical terminals inside the connector that make the actual electrical connection between the wiring harness and the headlights are typically oxidized or corroded, especially between the wire and the terminal.

The same high-beam filament requires substantially less current to keep it lit, in this case a bit more than 2.9 amps at 14.4 VDC. Factored as a percentage, this is 55 percent less current. Electric fans and pumps behave similarly; only their current requirements are substantially higher.

Numerous types of headlight systems are available. There can be two headlights, one on each side of the vehicle. In this arrangement, each headlight assembly has a dual-filament bulb, with one filament for low beam and the other for high beam. A vehicle can have four headlights, two on each side; one can be a low/high beam with a dual-filament bulb, and the other can be a dedicated high beam with a singlefilament bulb. This project illustrates the latter. Servicing either is similar. Part 1: Low Beams Perform voltage drop tests, which tell you if the headlight system requires servicing or not. This is an incredibly simple process, and it removes the guesswork of assuming your headlights should be brighter than they actually are. I mean, who can really tell by just looking at them? As you will perform multiple voltage drop tests in this process, write down your measurements with the headlights on, and then turn the headlights back off immediately after documenting your measurements to keep the battery from discharging. This process gives you the best data. In this example, I illustrate the process for Bill Surin’s 1970 Oldsmobile Cutlass S. Refer to Figure 2.1 for a diagram of the headlight circuit in this vehicle. It’s pretty simple. The easiest way to service such a circuit is to perform voltage drop tests across it. Let’s dissect the circuit into subparts to make this job straightforward:      

Power wiring to the headlight switch; it includes the power fuse. Headlight switch. Wiring between the headlight switch and the low/high-beam switch. Low/high-beam switch. Wiring between the low/high-beam switch and the headlights. Return path from the headlights to ground.

Figure 2.1. Note that I included letters at the connection points in Figure 2.1. I refer to them in the following procedures to make this job a snap. Regardless of what type of vehicle you have, this should be pretty similar. If you’re an electrical rookie, use the wiring diagram for the headlight circuit in your vehicle. For this era of GM vehicles, use the chart below.

Be sure ignition switch and all accessories are off. Remove the dome lamp fuse so that the dome lamp doesn’t draw the battery down over the course of testing, as you’ll likely have one or more doors open during the entire process. (This is an excellent habit to get into, by the way.) Measure voltage at battery. Set your digital multimeter to read DC voltage, place the probes in the correct locations, and read the nominal voltage of the battery. Document this.

12.58 VDC is the nominal battery voltage in this 1970 Olds Cutlass. This is the starting point, and it provides the foundation to calculate voltage drops as a percentage; more than 5 percent is an indication of a problem area. It’s really helpful to begin any process like this with a fully charged battery. Therefore, if you measure less than 12.5 volts, you should charge the battery first before proceeding. Follow the battery manufacturer’s guidelines, if necessary. Perform first voltage drop test. Connect the red probe of the digital multimeter to the main power input of the switch (A in Figure 2.1); this is the large wire that measures 12 volts with the switch in the off position.

Sometimes, accessing the headlight switch is a bear. You likely have to remove the headlight switch so that you can probe the wiring in the following steps. Removing this switch wasn’t fun, because it was difficult to access from under the dash. This style of switch has a small pushbutton (opposite side of the switch from the electrical connector) that allows you to remove the entire shaft. With shaft removed, you can then remove the mounting nut and, finally, the switch as an assembly. After the switch is accessible, use a probe-piercing adapter to connect the red probe of your digital multimeter to the main input wire. Slide the headlight connector back slightly from the headlight so that you can connect the black probe directly to the input terminal of the low beam of the headlight (F in Figure 2.1); do not connect the probe to the wire that feeds it. If you have multiple low beams on each side, you should begin with the connector that feeds the other (it typically has two wires in each of the low- and high-beam terminals).

Connect the black probe of your digital multimeter to the headlight. An alligator adapter makes this connection a snap.

A 1.19-VDC drop between the power input of the headlight switch and the driver’s low-beam headlight is pretty significant, as this represents a 9.5- percent drop in voltage.

A .69-VDC drop on the passenger’s side is better, but it still represents a 5.5-percent drop in voltage. Turn on the headlight switch, set the low/high-beam switch in the correct position, verify that the low beams are on, and note the reading on the digital multimeter. Document this for each low-beam headlight, turning off the headlights between measurements. The highest measurement you obtain represents the amount of voltage lost through the entire lowbeam circuit, which includes the headlight switch, the low/high-beam switch, the wiring harness, and all of the connectors and terminals. Some voltage drop is normal, but if you record 5 percent or more drop at any point in this process, service is required for that specific component or part of the circuit. See sidebar “Voltage Drop Calculations” on page 39 for an in-depth explanation.

Now that you have an overall feel for the state of health of the low-beam circuit, it’s time to find the source(s) of the voltage drop. This requires that you perform more specific voltage drop tests to find the part(s) of the circuit that is responsible for the voltage drop. I like to do the easy stuff first. Let’s start at the headlight connector end and work backward toward the source of power for the headlight switch. Let’s tackle the low-beam circuit first. All connectors on each side of the vehicle should be examined, especially if you obtained your greatest measurements during this step. Remove terminal from connector.

Insert a small flat-blade screwdriver into the plug body so that you can release the tab that holds the terminal in the body. Once the tab has been released, you can slide the terminal right out of the plug body. Inspect the integrity of the connection between the wire and the terminal. Look for signs of oxidation, corrosion, electrolysis, etc. These conditions are common in such a connector that has been exposed to the elements for 40 years! Also inspect the inside of the terminal for the same problems. Any of these things can cause diminished performance, as they are sources of resistance between the copper wire and the terminal on the headlight. If you find signs of oxidation, corrosion, or electrolysis, you can either repair or replace the connector(s). Chances are good that if you observe any of these conditions, you will also find them at the high-beam and ground terminals; it’s best to check them all at this point so that you can identify them as weak spots in the process. Don’t make repairs just yet; you need to evaluate the entire low-beam circuit first. Voltage Drop Calculations Consider a pair of 40-watt headlights. Remember, power is the product of current and voltage (Power = Voltage × Current). The following math is helpful: 80 watts ÷ 12.6 VDC* = 6.34 amps of current * Nominal voltage of a fully charged 12-volt battery

With a voltage drop through the system, current is also compromised, as voltage is what causes current to flow. You would have to measure this reduction on a bench with a power supply. No problem; you can do that. In this example, I connected a single stock headlight from a 1968 GTO to a 50-amp bench-top variable power supply. When I reduced voltage by 1.1 VDC, current flow is reduced from 2.7 amps to 2.6 amps. I have to take both into consideration to determine how much power is lost by this drop in voltage. Let’s use math to compare the two: 12.6 VDC × 2.7 amps = 34.02 watts 11.5 VDC × 2.6 amps = 29.90 watts 29.90 ÷ 34.02 = 87.9 percent, a 12.1-percent reduction Incidentally, if I just considered the voltage drop only, I could easily be misled, as 11.5 VDC ÷ 12.6 VDC = 91.3 percent, or an 8.7-percent reduction. This is a pretty substantial difference! More important, it represents a significant reduction in light output from the headlight.

Voltage is that which causes current to flow. More voltage equals more current into a non-regulated device, such as a headlight.

Look closely at the light pattern on the front of the power supply, and you will notice that there is significantly less light coming from the headlight at 11.50 VDC, even at this short distance. Perform second voltage drop test. Connect the red probe of the digital multimeter to the low-beam output of the low/high-beam switch (D in Figure 2.1), and connect the black probe directly to the wire that feeds the low-beam headlight (F in Figure 2.1). This allows you to determine how much voltage is lost through the run of wiring between the low/high-beam switch and the headlight. This includes any firewall or bulkhead connector (if applicable) that the wire passes through.

To access the low/high-beam switch, it is necessary to remove the kick panel trim and pull back the carpet and sound-deadening material. Unravel the tape on the harness, and use a piercing probe to connect to the low-beam output wire as shown here.

The .17 VDC of voltage drop between the low/high-beam switch and the low-beam headlight harness is insignificant on its own, only amounting to a 1.3-percent drop in voltage. If you find that you have a significant voltage drop over this run, you should remove and inspect the terminals in the firewall connector for corrosion, oxidation, or electrolysis. Remove the negative (–) cable of the battery before doing so. Perform third voltage drop test. Connect the red probe of the digital multimeter to the input of the low/high-beam switch (C in Figure 2.1), and connect the black probe to the low-beam output of the switch (D in Figure 2.1), which is typically the same color as the wire at the low-beam headlight. Document this.

Use a second piercing probe to connect across the low/high-beam switch. Connect the red probe to the input of the switch, and connect the black probe to the low-beam output of the switch.

The .10 VDC of voltage drop across the low/high-beam switch (low-beam setting) is also insignificant, as it amounts to a .7-percent drop in voltage. If you find significant voltage drop across the switch, you may have to replace the switch. If you can manually hold the switch down slightly, in any position that causes the voltage drop to be lessened, or if repeated switching causes different readings, it is an indication that the switch is worn out and needs to be replaced. Perform fourth voltage drop test. Connect the red probe of the digital multimeter to the output of the headlight switch (B in Figure 2.1), and connect the black probe to the input of the low/high-beam switch (C in Figure 2.1). This should be a pretty short run, and, given that it’s inside the interior of the vehicle, you shouldn’t record any appreciable voltage drop. Document this.

The .05 VDC of voltage drop between the output of the headlight switch and the input of the low/highbeam switch is also insignificant, as it amounts to a .4-percent drop in voltage. Ok Perform fifth voltage drop test. Connect the red probe of the digital multimeter to the input of the headlight switch (A in Figure 2.1), and connect the black probe to the output of the headlight switch (B in Figure 2.1). Document this.

The .72 VDC of voltage drop across the headlight switch is significant, as it amounts to a 5.7-percent drop in voltage. This switch has to be repaired, replaced, or otherwise addressed.

Again, if you can manually move the switch to any position that causes the voltage drop to be lessened, or if repeated switching causes different readings, it is an indication that the switch is worn out and needs to be replaced. Verify power connection to headlight switch. Now that you have checked the entire headlight circuit, you need to check the integrity of the power connection to the headlight switch. Perform the sixth voltage drop test. Connect the red probe of the digital multimeter to the battery positive (+), and connect the black probe to the input of the headlight switch (A in Figure 2.1). Document this. This shows how much voltage is lost between the positive (+) side of the charging system and the headlight switch. This includes any power junctions, connections to the input of the fuse panel, connections between the fuse and the fuse panel, the fuse, and connections between the fuse panel and the headlight switch. Measurable drop here requires servicing. You can narrow that down precisely, just as you have done with the headlight circuit.

The .16 VDC of voltage drop between the battery and the headlight switch is also insignificant, as it amounts to only a 1.3-percent drop in voltage. Check integrity of return path to ground from the headlights. Connect the red probe of the digital multimeter to the ground wire of the low-beam headlight (H in Figure 2.1), and connect the black probe to the battery negative (–). Measurable drop here means one or both of the following apply:  

Battery’s negative (–) connection to the chassis needs servicing. Headlight harness’ connection to the chassis needs servicing.

Either could mean that the connection of the terminal to the wire is oxidized or corroded, the connection between the terminal and the chassis is oxidized or corroded, or both.

The .03 VDC of voltage drop between the ground wire of the driver-side low-beam headlight and the battery negative (–) post is insignificant, only amounting to a .2-percent drop in voltage.

Passenger-side voltage drop is even less significant.

Part 2: High Beams Repeat Steps 3, 5, and 6 of “Part 1: Low Beams” for the high-beam headlights. Be sure you have the low/high-beam dimmer switch in the correct position for high-beam operation before starting. Here is what I documented in the 1970 Cutlass:

Make the Appropriate Repairs Based on the data acquired in the process, you now have to determine the most cost-effective way to service the system to restore it to its original level of performance. The information obtained in Step 5 is really the most relevant data collected when you take into consideration the cost of replacing parts of the wiring harness, as they are the most expensive. Depending on the condition of the terminals and connections in the firewall connectors, you may have to replace the harness from the firewall forward. In severe cases, you may have to replace the entire wiring harness in the vehicle. Either is expensive.

You may also need to replace the headlight switch and/or the low/high-beam switch. Before making any repairs, you should determine the cost of the repairs necessary to restore original performance. If it gets very expensive, a far more cost-effective option is to eliminate the effect of voltage drop by adding relays to the headlight system. (This is illustrated in Project 4: Upgrading the Stock Headlights to Higher-Powered Units.) If, in Step 4, you found terminals within the connectors that need to be replaced, you can either replace the entire connector or only the terminals. A well-stocked auto parts store sells the U-barrel-type terminals that crimp on the wire. You can buy a box of these for about half of what it costs to replace all of the connector pigtails. If you do not own the correct crimping tool, it likely is more cost-effective for you to replace the connector. Servicing Firewall Connectors It’s an expensive proposition to replace either part of the wiring harness because of poor connections between the terminals in the firewall connectors. But, all is not lost yet. You may be able to remove the old grease; clean the terminals within each connector, re-grease them, and dramatically reduce the voltage drop across these connectors. This process doesn’t cost anything, so it’s best to at least try it before purchasing new harness parts. Keep in mind that if you have identified voltage drop through these connectors with the headlight circuit, chances are good that you will find the same problem for all other circuits that pass through these connectors.

Here is the firewall (or bulkhead) connector in the 1970 Olds. If the vehicle was involved in a collision, and the harness was damaged, this connector would allow the front clip to be replaced without having to replace the entire wiring harness. It is removed via the single 3/8-inch bolt in the center of the connector.

With the connector removed, the terminals can be accessed. Because this is a weatherproof connector, the terminals within it are in excellent condition, even though this vehicle was originally a Chicago car The goop on the terminals is grease designed to promote a good connection. Both halves of this connector are in excellent condition. If you overload a circuit that passes through a connector like this, the terminals and the connector become damaged from heat, and repairing this connector is costly and time consuming. In the 1970 Cutlass, three repairs were necessary: 1. 2. 3.

Replace corroded/oxidized terminals in the headlight connectors (determined in Step 4). Replace the headlight switch. Address or repair the voltage drop between the low/high-beam switch and the headlights.

After you have made the appropriate repairs, repeat Steps 1 through 3 to perform a second voltage drop test to check the effectiveness of your work. Do this for each low- and high-beam headlight. Document each. The voltage drop for low beam and high beam should have been reduced accordingly. The end result should be minimal voltage drop throughout the entire headlight circuit so that maximum voltage can be delivered to the headlights, thereby maximizing their light output. Through this process, you will likely find numerous small problems. On their own, they are not a big deal, but the sum of all of these small problems can definitely add up. After you have completed the repairs, there will be no doubt that your headlights are performing to the best of their ability. Project 4: Upgrading the Stock Headlights to Higher-Powered Units This upgrade is the most obvious and easiest modification to make to improve night driving in any classic vehicle. Adding the latest and greatest in modern halogen lighting to such a vehicle puts a far greater demand on the switches, wiring, and connectors than what they were designed to accommodate. The connectors on most high-power modern headlights are identical to the existing pigtails on the wiring harnesses in these vehicles, so they appear to be plug-and-play. They are most certainly not. Plugging modern, high-power headlights directly into a stock harness can damage the connectors, the wiring harness, and even the switches, especially if they are in need of servicing or replacing, as outlined earlier. A worst-case scenario is a fire that results from excessive heat in any of these components.

Therefore, it is necessary to take steps to correctly power them. Fortunately, this is easy. This upgrade requires one relay per low- and high-beam circuit. You need these parts:   

(2) Hella weatherproof relays (2) Hella weatherproof relay sockets (4) Headlight connector/pigtail assemblies, Dorman PN 85810 or Painless PN 80300

Figure 2.2.

I built my own wiring harness for this circuit. You may want to purchase a pre-made harness. I had two Painless connectors (PN 80300) on hand, and I purchased a pair of Dorman connectors (PN 85810) at a local auto parts store. Also shown here are all of the parts required to assemble the Hella weatherproof relay sockets, including the sockets, seals, terminals, and mounting tabs that snap into the relay bodies.

Because you are most likely mounting the relays under the hood, use relays designed for this purpose. I use skirted SPDT relays and sockets from Hella, because they are weatherproof, perfect for underhood use. SPDT (single-pole dual-throw) relays have five tabs for common (#30 in Figure 2.2), normally open (#87), normally closed (#87a), and two coil connections (#85 and #86).

CE Auto Electric Supply offers many complete kits. This H4 kit is designed for vehicles with a single headlight on either side. Except for the connections to the battery and ground, it is truly plug-and-play. Companies, such as Painless, offer relay kits designed to make this interface simple. They are truly plug-and-play, eliminating the need to build your own circuit. Yes, you can use this exact procedure to eliminate the effect of voltage drop. This could save you a lot of money compared to replacing the switches, parts of the wiring harness, etc. I’ll go through the steps in the 1970 Olds Cutlass to see just what kind of improvement can be made. (I’m going to stick with the existing headlights to illustrate the improvements that can be made electrically. Afterward, the owner of this car can upgrade the headlights, if he chooses, with significantly higher-powered units without worry of overloading the wiring.) Assemble relay sockets. If you purchase a kit, such as one offered by Painless, the relay sockets come fully assembled. All you typically have to do is plug them in and connect power to the battery. By now, it should be obvious that I make most of my own harnesses. If you elect to do that as well, refer to Step 6 of Project 7 in Chapter 4 for more detail.

The relay sockets have been fully assembled and will make an excellent foundation for building the complete harness.

Integrate headlight connectors into harness.

After determining the appropriate location on the harness to splice in the headlight connectors, solder them to the harness according to Figure 2.2. Insulate these connections with heat-shrink tubing. Do this on the workbench for both the driver’s side and passenger’s side.

This is a completed harness, which is ready to be installed in the vehicle. The two loose black wires on each end are the ground wires for the headlights. Mount relays.

Mount the relays so that the wiring points downward. This arrangement reduces the likelihood of water entering through the seals.

Plug in harnesses. Whether you built your own harness, as I did, or purchased a kit, it’s plug-and-play. Simply unplug the OEM headlight connectors, lay them to the side, and plug in your own. Be sure to get the three-wire connector plugged into the dual-filament headlight on both sides. Ground headlight connector harnesses. The loose wires shown in Step 2 need to be connected and grounded. Use a star washer and white lithium grease to ensure a low-resistance, weather-resistant connection.

I used split-loom tubing to cover the harness as it crosses the core support in front of the radiator. I grounded the headlights to the core support, as they were from the factory. Interface relays to stock wiring.

Locate the wiring to the first headlight connector. Interface the relay trigger leads. I always recommend soldering and taping such a connection that is under the hood. Don’t even consider a T-tap or Scotchlok for this.

Source power for relays. You have a few choices here: tie the relay power leads directly to the battery positive (+), or tie them to a convenient power junction point (which will be connected directly to the battery positive, such as in GM vehicles with side post batteries), or tie them to an auxiliary fuse panel. Either way, each relay needs to be fused within 18 inches of the source of power with a 20-amp fuse. I actually did Project 10 in Chapter 5 before I did this project (see that project for more detail if you elect to do it that way).

If you don’t have a convenient underhood place to source power for accessories, connect the power leads from the relays directly to the battery positive (+) post, and fuse each within 18 inches of the battery with a 20- amp fuse.

I now have a .07-VDC (total) voltage drop between the battery positive (+) post and the low-beam headlights. This amounts to a .6-percent drop across the entire low-beam circuit.

I now have a .15 VDC (total) voltage drop between the battery positive (+) post and the high-beam headlights. This amounts to a 1.2-percent drop across the entire high-beam circuit. Yes, this is a massive improvement over what you began with! Consider the worst-case-scenario total voltage drop from the battery positive (+) to each of the beams:

Keep in mind that all of this data was obtained with the ignition switch off and the engine not running. With the engine running and the alternator charging, voltage to the headlights improves from 12.6 VDC to 14.4 VDC. Remember what you learned in the sidebar, “Voltage Drop Calculations” on page 39 and the effect that has on the output of a headlight.

14.40 VDC × 2.9 amps equals 41.76 watts. Compare this to the data presented in sidebar “Voltage Drop Calculations” on page 39 to fully grasp the benefit of eliminating voltage drops. Now contrast the light output shown here with that shown in the sidebar. This will give you an idea of the kind of improvements you can expect to see in your vehicle when completing this project. Summary With the engine off, the first thing that Bill noticed was that the headlights now shined bright white; before they had a yellow hue to them. During a quick test drive, he simply could not believe how much of a difference this simple upgrade made to the low beams. The high beams are, in Bill’s words, “Night and day!” It truly is amazing how much light they put out now. And the best part is that we didn’t have to replace the OEM headlight switch, as the voltage drop through it is no longer a factor. This simple upgrade provides increased visibility for nighttime driving. You’ll wonder how you got by before!

CHAPTER 3 PERFORMANCE GAUGES Adding aftermarket gauges is very popular, and for good reason. They are far more accurate than OEM gauges. In addition, they give your vehicle some performance cosmetic appeal. No, mounting a 5inch Monster tach in the corner of the dash of your otherwise stock vehicle won’t make it any quicker, but it may get you constant solicitations for a street race by those with much faster vehicles. A good set of aftermarket gauges provides excellent data about the engine’s operating status. And, without hesitation, you should trust them! For example, I was cruising in my Olds on the strip one Saturday night, and I noticed the coolant temperature gauge climbing steadily past the 200-degree mark; it normally reads 185 degrees or so maximum at night around town. As I made a lap, it continued to climb past the 220-degree mark. After I tapped the gauge (hey, we’ve all done it!) to be sure it was reading correctly, and it didn’t move, I pulled into an empty parking lot. By that time, it registered near 250 degrees, an indication that something was very wrong. After the engine cooled, I quickly diagnosed that either a head gasket or an intake manifold gasket had failed, as the radiator was half full, and there was water in the oil.

This set of Auto Meter Elite Series 2 inch gauges represents the state of the art in aftermarket gauges. Everything needed for most installations is included with each gauge. In my opinion, high-quality aftermarket gauges are a necessity in a performance vehicle. They are readily available from AEM, Auto Meter, Megan Racing, Nordskog, Stewart Warner, and others. So, what’s new and exciting in the world of aftermarket gauges? Are they really that different from that three-gauge set that the local swap meet sells for $19.99 with a free air freshener? You bet! Gauge Types There are two types of gauges: mechanical and electric. Mechanical gauges are most often found in vehicles that compete in racing events, as they offer the utmost in accuracy and have a direct connection to that which they are monitoring. Many enthusiasts also prefer mechanical gauges in their street/strip cars, or even street cars, for this reason. Electric gauges differ in that a sending unit is installed at the source, and it’s connected to the gauge with a minimum of one wire.

I’ve always used a combination of both in my vehicles. I prefer mechanical gauges for vacuum/boost and oil pressure, because they are typically easy to install. Coolant temperature gauges can be a different story, unless you have an unused 1/2-inch NPT tap in your intake manifold or cylinder head. Fuel pressure is also tricky. Sure, it’s easy to find a location to tap the gauge, but it isn’t safe or advisable to run a line of fuel into the interior of the vehicle. Your vehicle will also not pass tech at the local drag strip if it has a fuel line passing through the firewall and into the passenger compartment. True, you can buy a mechanical fuel pressure gauge with an isolator (Auto Meter offers one), but these are really not intended to be installed in street-driven vehicles. Exhaust heats the isolator over time, and the gauge reads high as a result. Electric gauges are typically a far better bet for monitoring coolant temperature and fuel pressure in street-driven vehicles. Some mechanical gauges, such as temperature gauges, have hard lines that cannot be disconnected from the rear of the gauge. This can make it very difficult to remove the gauge or panel that holds it without first removing the sending unit. Remember the 1967 Mustang that I discussed earlier? The cluster in that car had mechanical coolant temperature and oil pressure gauges. The lines between them and the engine had almost no slack in them. This made it extremely difficult to remove the cluster; bad planning from the start. Until recently, for most enthusiasts, choosing between mechanical and electrical came down to which was easier to install. Well, guess what? That has all changed! Today’s electric gauges are fully electronic and offer numerous features that were simply unavailable previously. These are perfect for street, street/strip, and even competition vehicles. For example, you can now install a coolant temperature gauge that can be programmed to trigger a relay to turn on an electric fan at a user-set temperature. Or, how about a tachometer that illuminates white during normal operation, and, at a userprogrammed shift point, the entire face of the tach changes to bright red? How cool is that? Project 5: Installing a Complete Set of Fully Electronic Gauges By now, it should be obvious to you that my Mustang is a guinea pig of sorts when it comes to adding the latest and greatest in aftermarket electronics. This vehicle is outfitted with a staggering amount of aftermarket electronics and performance goodies, yet there isn’t a trace of wiring out of place and everything is properly protected. If you take your time with each project and never allow yourself to fall into the “just get it done” attitude, your vehicle will turn out the exact same way. This project requires a substantial amount of mechanical preparation on the front side. True, the gauges simply plug into the harnesses, but to get to that point takes time. Earmark the better part of a day for this project if you want it to come out looking like mine. Don’t start the project until you have all of the parts in hand that you actually need; this includes any adapters required to install the sending units. These components are:     

(1) Auto Meter 2 (1) Auto Meter 2 (1) Auto Meter 2 (1) Auto Meter 2 (4) Auto Meter 2

inch Elite Series oil pressure gauge (PN5652) inch Elite Series coolant temperature gauge (PN5654) inch Elite Series fuel pressure gauge (PN5671) inch Elite Series vacuum/boost gauge (PN5677) inch universal gauge mounting cups (PN2204)

Note: Some Ford 4.6L engine blocks require a metric-to-NPT adapter (Auto Meter PN2268) to install the coolant temperature sending unit into the block. These gauges are microprocessor-controlled, LED-backlit, full-sweep electric gauges that have a host of state-of-the-art features. The meter movements are via stepper motors. The LED lighting can be userset to any one of seven different colors for all features. The gauges offer a peak recall feature that is easily reset-table, perfect for recalling a maximum reading after a run. One of the coolest features these

gauges offer is the ability for the user to program the gauges to change the illumination color for user-set low- and high-warning points. In addition, the user can program the gauges to change the illumination yet again at low- and highwarning points; only these also flash. If that weren’t enough, the gauges have programmable outputs that can activate relays based on three ranges: below the low warning point, between the low and high warnings, and over the high warning ranges (Auto Meter calls these Pro Control). Finally, each gauge has a data logger output for use in competition. Consider the following example with the PN5654 coolant temperature gauge:

When the vehicle is started and the gauge illumination is turned on, the gauge illumination is green until the coolant temperature reaches 180 degrees. At that point, the illumination changes to blue, and the Pro Control output becomes active, thereby switching on a relay for an electric cooling fan. If the coolant temperature climbs to 230 degrees, the gauge illumination automatically switches to yellow, alerting the operator. If the coolant temperature climbs to 240 degrees, the gauge illumination automatically switches to red and flashes to warn the operator to shut off the engine. For large projects such as this one, planning is a must to ensure that it goes smoothly. My standard procedure is to first define the objective, then outline any special considerations, and finally list the parts required. I typically create a diagram, but this project isn’t large enough to warrant this. Define the Objective In this installation, my objective is to mount the gauges in a unique location, not in the A-pillar. I also didn’t want to use one of those gauge housings that mounts atop the dash just above the A/C vents, because I really didn’t want to drill a big hole through the top of the dash (the housings only hold two gauges, anyway). Rather than use any exotic parts, I used all off-the-shelf parts; you can easily replicate a similar installation, no matter what kind of vehicle you drive. The 1994 to 2004 Mustangs have a large vacant area below the windshield and at the front of the dash. In addition, the defroster duct trim piece spans the dash and is easy to remove (it simply pops off). This is the perfect location for a cluster of gauges. Be warned that the gauges reflect onto the windshield at night when mounted in this location.

Outline the Considerations I wanted this installation to be easily reversible should I ever decide to sell the vehicle. To that end, this installation requires:    

Coming up with a scheme to mount the gauges to the duct trim piece. Routing the wiring down through the dash without drilling a visible hole in the dash. Drilling a hole in the firewall because the existing grommet is maxed out. Installing each of the sending units.

List the Parts Required This installation calls for some kind of material to use in the construction of the gauge mounting bracket and some hardware to assemble it. The mounting bracket can be made from steel, aluminum, fiberglass, or a combination of materials for a custom finish. If you’re trying to keep things simple, you can use 1/4-inch-thick MDF (very easy to work with) or 3/16-inch-thick ABS plastic. I chose ABS plastic, as it is super easy to work with, and it doesn’t have to be painted.

I use Painless PowerBraid (left) for many of the projects in this book. The finished look is exceptionally clean. Painless also offers installation tools (right). This project requires the following parts:        

Piece of 3/16-inch-thick ABS plastic (1 square foot should be enough) 1/2-inch × .257 × 1/2-inch nylon spacers, Hillman PN 880437 * 1-foot aluminum angle stock, 3/4 inch × 1/2 inch * Nitrous Outlet billet adapter Assortment of 10-24 screws, washers, and bolts * Painless 1/8-inch PowerBraid, PN 70910 Painless 1/4-inch PowerBraid, PN 70901 1-inch-diameter rubber grommet

* Available at your local hardware store.

The aluminum angle stock gives the mounting base some extra rigidity, which keeps it from flexing when the vehicle is in motion. Remove defroster duct trim piece.

The defroster duct trim piece simply pops off. Start at the sides and work your way toward the middle, being careful not to break off any of the plastic clips. I didn’t use any tools, just my fingers, and it came right off. Mock up the gauges for mounting.

Place the empty gauge-mounting cups along the top of the defroster duct trim piece. This gives you a good idea of how to construct the mounting base to accommodate the gauges.

I chose to angle the gauges toward the driver, keep all gauges at the same angle, and place them closely together to take up as little room as possible. With all gauges at the same angle, the center two gauges will be spot-on for viewing from the driver’s seat, and the outer two gauges will be off slightly. Feel free to angle them as you prefer. Make mounting plate from ABS plastic. ABS plastic is very easy to work with. All you need to cut it to shape is a flat surface, a scribe tool, and a straightedge. Flip the ABS over so you have the shiny side facing up and the textured side facing down. Measure the width of the piece and make two measurement marks with the scribe. Then, using the straightedge as a guide, repeatedly run the scribe down the length of the plastic until you have a deep score. When the score goes about one third of the way into the plastic, you can simply break it off on the end of the workbench. Repeat this process to get the exact shape you desire. Do not attempt to cut ABS plastic with a jigsaw or cut-off wheel, as it fuses itself back together in the process. After you have attained the exact shape that you’re after, you may choose to chamfer the edges of the plastic as I did to give it a more professional look.

Here is the plastic mounting base. Drill 3/16-inch holes for no. 10 screws to mount the gauge mounting cups in place. I used a T-bevel (Step 7) to get the bases exactly where I wanted them when marking for the holes.

Mock up bases.

Each of the gauge mounting cup bases fit on the mounting base like this. Drill corresponding holes in aluminum angle stock.

The aluminum angle stock should fit under the rear of the mounting base; so that the part that points down sits inside of the groove in the defroster duct trim piece (see Step 7). Drill corresponding holes in the aluminum angle stock to match up with the four rear mounting holes for the bases. Drill holes in defroster duct trim piece.

Mock up the bases for the gauge mounting cups. Each of the cup bases fits on the mounting base. Drill two 3/16-inch holes in the defroster duct trim piece to match up with the left two rear holes on the mounting base. This holds the entire assembly in place.

Mock up assembly.

The bases for the gauge-mounting cups are designed to fit flat or round surfaces. I used no. 10 washers under them to keep the ABS plastic absolutely flat while tightening the screws; otherwise, it tends to curve.

Use the T-bevel to get the exact alignment of the bases when mounting them. Even though you are mocking the assembly, this shows you exactly how it will look when finished.

Mount the bases to the ABS plastic with 1-inch-long 10-24 screws. These have to be trimmed to length to clear the dash panel. The two rear left screw holes are empty; this is intentional.

The assembly should look like this from the bottom. Mount assembly to defroster duct trim piece.

Insert the two 1½-inch-long 10-24 screws through the defroster duct trim piece from the bottom. Slide the nylon spacers onto the screws.

Bolt the assembly together. This is very rigid, thanks to the aluminum angle stock.

The screw heads protrude slightly from the bottom of the defroster duct trim piece, but this is not a problem. When the trim is installed, these screw heads indent the material on the dash, allowing it to fit totally flat.

This assembly fits very well and is structurally sound. Trial-fit assembly. Now that you have a fully assembled base, snap the defroster duct trim piece back into the dashboard and temporarily mount the gauge cup brackets to the base (not the cups themselves). Then, trial-fit the cups into the cup mounting brackets. Hint: Leave the cup bracket screws very loose, squeeze the cups a little bit, and slide them into the mounting brackets from the front. This process is tedious and somewhat difficult because you don’t have much room between the gauge brackets and the windshield. The mounting cup brackets allow you to move the mounting cups fore and aft to get the right location. Make a mental note of this for final assembly. After you’re happy with the fit, remove the assembly from the vehicle. Unbolt the mounting base from the defroster duct trim piece. It will be reassembled in the vehicle. Remove lower dash trim pieces. In this step, you need to remove the lower dash trim panel and knee bolster to make accessing the lower dash area easier. Also remove the trim bezel around the radio and A/C controls to allow easy routing of the gauge harnesses to the upper dash. Prep the gauge harnesses.

Prep each of the gauge harnesses for installation. Group the power, ground, and illumination leads, which are 18 inches long, in one bundle with Super 33+ tape. Group the Pro Control and data logger leads in another bundle with the tape. Finally, use tape to group the sending unit wires neatly. Do this for each gauge.

Cover the gauge side of each gauge harness with PowerBraid; 18 to 24 inches is fine. Label each harness (as the gauge connectors are all identical) so that you can easily tell them apart during final assembly. I used white heat-shrink tubing for this. Label the Pro Control and data logger grouped leads for each gauge so that you can tell which is which. I used blue painter’s tape for this. Drill hole in firewall. These gauges are plug-and-play. Drill through the firewall so the harness can pass through it. Each of the included harnesses has a pre-terminated plug on each end. A 7/8-inch-diameter hole must be drilled in the firewall to accommodate the rubber grommet.

So, any questions why I preach about using grommets and snap bushings when passing wiring through a metal barrier? I drilled this hole with a 7/8-inch hole saw from inside the vehicle, and it was very hard to get the drill and hole saw into this area because the clutch and brake pedals are right in the way. Hole saws sometimes leave nasty edges on the other side of the surface when they pass through. Clean the metal shards from the hole with a long flat-blade screwdriver, if needed. A Blue Point deburring tool is specifically made for this job. Feed harnesses through firewall. Feed each of the smaller plugs (the gauge side) from the engine compartment side through the firewall and into the passenger compartment. It is necessary to feed all four harnesses through before installing the grommet into the metal to protect them. Be very careful that you do not damage the wire insulation on the sharp edges of the metal. A helper is a good idea here.

The fun begins! For now, just leave all of the harnesses on the floor. Notice the labels on each. How else would you be able to tell them apart?

This is where things get a little tricky, as you really want only enough of the harness in the engine compartment to reach the sending units, and no more. For now, just leave them loose.

Route the harnesses to the left of the clutch pedal. A factory harness comes through the firewall just above and to the left of the hole I drilled. The plan is to follow it and keep the harnesses up and out of the way of the pedals, etc. For now, leave all of this loose. Route harnesses to upper dash area.

At this stage, feed the gauge side of the harnesses to the upper dash area. Below the steering column, the knee bolster conceals a factory harness. The plan is to follow it and tie the harnesses to it. For now, route the harnesses accordingly so that they can be neatly tied to this factory harness, but don’t tie them up yet. The easiest way to get the harnesses to the location in the center of the dash is to route them to the area just above the A/C controls first. Drill 1-inch hole in dash. Drill a 1-inch-diameter hole in the top of the dash, under the defroster duct trim piece. Drill this hole directly under the defroster duct trim piece so that it is completely hidden when the trim piece is installed. Drilling a hole so close to the windshield requires some specialized tools and extra caution to avoid breaking the windshield. I used a carbide hole saw and a right-angle adapter for the drill to make this job a snap. I really can’t think of any other way to drill the hole in the dash, given its close proximity to the windshield. You can buy carbide hole saws at any home improvement center. The rightangle adapter is from Spec Tools (PN HD-90).

I used this carbide hole saw to drill the hole into the top of the dash, because it easily cuts through metal of all kinds. It also has a hex shaft on it, which locks into the rightangle adapter shown here. As an extra precaution, place your hand between the right-angle adapter and the windshield; do not allow the tool to contact the glass when drilling, or you will break the windshield. Finally, be careful when the hole saw is through the metal of the dash, as the plastic ductwork is directly below, and you don’t want a big hole in it.

Route harnesses to dash.

Route the harnesses to the gauges from the area over the A/C controls to the hole that you just drilled. I used a 3-foot-long cable tie as a fish tool, fed it into the top of the dash, and snaked it out above the A/C controls. This is a very tedious step, so take your time. Install defroster duct trim piece. Note the location of the hole in the dash and drill a corresponding 7/8-inch-diameter hole in the defroster duct trim piece that allows the harnesses to pass through it from the bottom.

The hardest part of the job is now behind you. At this point, all harnesses should still be loose in the vehicle. Feed the harnesses up through the defroster duct trim piece, and then snap it into place. Be sure that you have the 1½-inch-long 10-24 screws in place before snapping the trim piece into place.

Modify aluminum angle stock. In order to allow passage of the harnesses, you need to cut a notch in the aluminum angle stock that correlates to the hole you drilled in the defroster duct trim piece. Therefore, the notch must be large enough to allow the gauge harnesses to come up through the hole in the defroster duct trim piece and around the rear of the mounting bracket to the gauges. Don’t cut this notch too high up in the aluminum, because this greatly reduces its rigidity, which is the exact reason to use it to begin with. Cut it about one half to two thirds of the height of the aluminum angle stock and about 1 inch wide to allow the loomed harnesses to easily pass through to the gauges. The easiest way to do this is to remove the aluminum angle stock from the mounting base and temporarily slide it on the 10-24 bolts in the dash (be sure the nylon spacers are in place) to mark it exactly where you need to cut it. Trial-fit this piece to be sure the harnesses fit through the notch you cut. Remember, you can always cut off more, so take your time. Once you are happy with the fit, paint the aluminum black so that it blends in nicely after final installation. After the paint dries, reattach it to the mounting base. Pull harnesses through the dash. Pull about 12 to 15 inches of harness for each gauge up through the dash so that you can easily plug in the gauges when installing the final assembly. (You make each to the correct length in Step 20.) Install gauge mounting bracket. After the harnesses are properly routed, it’s time to mount the gauge mounting bracket down to the defroster duct trim piece for the final time. Before mounting the bracket, stick a strip of 3/8-inch-thick, 3/4-inch-wide foam weatherstrip tape to the underside of the ABS plastic in front of the aluminum angle stock. If you locate the weatherstrip tape back about 1/4 inch from the front of the plastic, it’s very hard to see. This conforms to the dash and keeps the whole assembly stable when the vehicle is in motion. Determine locations for sending units. At this time, you need to figure out the location of each sending unit. First, raise the vehicle and support it with jack stands, so that you can access the underside of the engine.

A 1/8-inch NPT plug is in the bottom of this T directly below the oil filter on most 4.6L SOHC engines. This is an ideal location for the sending unit for the oil pressure gauge. As you can see here, I have an oil feed line (to the Vortech supercharger) in that location. No problem; I just need a brass T to connect to the sending unit.

An ideal spot for the sending unit for the coolant temperature gauge is where this plug is installed in the block on the driver’s side near the firewall. A pipe plug with an internal hex is an indication that it has standard pipe threads, and the adapter included in the kit with the gauge matches perfectly. If the plug has a hex-bolt head, it is metric and requires the no. 2268 adapter.

Most 4.6L SOHC engines have a Schrader valve located on the passenger-side fuel rail. You could tap the sending unit for the fuel pressure gauge here, but I prefer to retain this valve, because it allows you to release the pressure from the fuel system, which is handy when changing the fuel filter. This is also where fuel injector cleaner can be introduced into the fuel system. Let’s leave it. Wrap each harness. To protect the harnesses, wrap each one in 1/8-inch Painless PowerBraid. You only want to use as much PowerBraid as necessary to cover the sending unit harnesses in the engine compartment. To that end, roughly route the harnesses to the locations of the sending units. Give yourself 12 inches of slack, just in case.

Once you begin using PowerBraid, you will likely want to continue using it, because it looks awesome, and it gives your wiring a uniform and professional appearance. Terminating the end in a tidy look is simple. Begin by leaving the last inch or two off the wiring.

Wrap some Super 33+ tape one to two times around the wiring in the same direction as the PowerBraid wraps around the wiring. Slide the PowerBraid over the tape and the wiring, with the tape hanging out the bottom.

Wrap the tape around and down the PowerBraid a few times. I tear the tape to length, but you may cut it to length with scissors. You don’t want to stretch the tape in this process, as it pulls loose as it shrinks. The finished termination looks super clean.

Repeat for each of the other sending unit harnesses. Install coolant temperature gauge sending unit. When you remove the block plug, you are going to make a giant, world-class mess. Be sure to keep your pets away from the coolant. I drained the radiator before pulling this plug, but it didn’t seem to help, so don’t waste your time. Get your biggest catch pan ready.

Install the sending unit into the block using the supplied adapter. Not pictured is the lake of coolant that was under the vehicle prior to taking this photo.

If you have aftermarket headers, cover the harness to the sending unit with 12 inches of hightemperature thermal wrap to protect it. I tied the harness along the dipstick tube to keep it as far away from the headers as possible. Per the instructions supplied with the gauges, use Teflon tape (or paste) on all NPT threads. Of course, after you get the vehicle back on the ground, you need to replace the coolant before starting the engine. Install oil pressure gauge sending unit.

My installation requires a 1/8-inch NPT T: one male to two females. Yours may not. If you do not have the 1/8-inch NPT plug at the bottom of this casting, you have to use a T at the outlet for the stock oil pressure sending unit (coming out to the left).

Install the sending unit.

I used a 1/8-inch NPT right-angle adapter to connect the feed line to the supercharger to the T. Admittedly, that’s a bunch of stuff, but it works great. Install MAP sensor.

Install the MAP sensor with the vacuum barb pointing downward (per the instructions) for the vacuum/boost gauge. I mounted it to the cowl trim with two 1½-inch-long 10-24 screws.

Plug in the MAP sensor.

Install fuel pressure gauge sending unit. I’m really not hip on losing the Schrader valve to add a fuel pressure gauge. There is another solution for these engines. Nitrous Outlet offers a billet adapter that mounts between the fuel rail and the OEM fuel pressure regulator. It has two 1/8-inch NPT outlets: one for a fuel pressure gauge and another to supply fuel to a wet nitrous system. Clever.

The stock fuel pressure regulator is located on the driver-side fuel rail.

This kit from Nitrous Outlet is super simple to install and inexpensive. The billet adapter has two 1/8inch-NPT outlets and two O-rings to prevent leaks. Also included is a 1/8-inch NPT-to-flare (-4 AN) adapter, a 1/8-inch NPT plug, and two longer bolts that are required to mount the unit in place.

Installation is a snap. The sending unit must go on the inside because it won’t clear the plug to the coil or injector on the other side. Pull any extra slack in the wiring from the sending unit harnesses through the firewall, so it can be tied up inside the vehicle. At this point, go ahead and tie up the harnesses for the coolant temperature and oil pressure sending units. Leave the fuel pressure and MAP harnesses loose, but routed. Complete wiring to gauges. At this step, complete the wiring to the gauges inside the passenger compartment. Use only one cable tie to tie the gauge harnesses up under the dash and as high up by the console as possible. This creates a service loop, so that the gauge harnesses can be easily pulled up and the gauges disconnected if you ever need to do that. Be sure that you have enough slack in the harness between the console and the hole drilled in the firewall to route it along the factory harness below the steering column and under the knee bolster.

Group the wiring from the gauge harnesses accordingly: power/ground, illumination, and Pro Control and data logger outputs.

Use your DMM to locate the dimmer output of the headlight switch; it is active with the parking lights and varies in voltage when rotating the dimmer. Piercing probes are very handy for this, and they leave only a tiny hole in the wire insulation.

This is the correct wire (blue with a white stripe), as indicated by 7 VDC in the middle of the dimmer’s rotation.

Solder the illumination leads to the dimmer output wire. I previously had a vacuum/boost gauge installed, so I cut the wire to it and used push-on connectors to make this connection. (This comes in handy shortly.)

Tie the wiring to the stock headlight switch harness. I installed the ATC fuse panel (see photo below) several years ago. I mounted it on the left side of the console structure behind the carpet. The 30-amp relay to the left is used to switch power to the panel

according to the position of the ignition switch. The panel is live when the key is in the IGN/RUN position.

And behind this door is an eight-position ATC fuse panel for switched accessories with two openings. If you have a bunch of aftermarket accessories, consider adding an auxiliary fuse panel (or two) to provide a place to connect the accessories. Crimp a 16-14-AWG, 3/8-inch-diameter ring terminal to all four of the ground wires from the gauges. I assume you don’t have such a fuse panel. No problem; simply use your digital multimeter to determine which of the wires in the ignition switch harness (covered by the gray plastic cover) is live in the ignition and start positions; this is the IGN/RUN wire, and it is the correct wire to tie the power lead for the gauges to. Solder one end of an in-line ATC fuse holder to this wire to protect the run of wiring between the ignition switch harness and the gauges.

It is necessary to lengthen the power wiring to the gauges to reach the source of switched power. Because the gauges don’t draw much, use a length of 16-AWG wiring for this.

Ground the gauges. I used a large 8-mm bolt for all of the low-current accessories that source power at this fuse panel. As always, use a star washer between the ring terminal and metal to ensure a good bite.

Connect the power lead to the source of switched power. As discussed earlier, this must be fused to protect the wiring.

Install a 5-amp ATC fuse.

Mount and connect gauges. Install each of the gauge cup brackets (screw in loosely) and lay them forward on the dash. Begin with the gauge on the far right, and install the gauge cup loosely in the bracket. Put the corresponding harness through the rear of the gauge cup, and pull it through to the front of the gauge cup; this is why you need a little extra harness. Plug the gauge into the harness, and slide it into the gauge cup. Locate the gauge cup at the correct depth in the bracket and at the correct angle for best viewing at your preferred seating position. For now, leave the extra harness on top of the dash. Tighten the screws for the gauge cup bracket. Repeat this process for the remaining gauges. Pull the extra harness for each gauge down through the dash to get them to just the right length. At this time, you can install the trim bezel around the radio and A/C controls. Test gauges. Now it’s time to start the vehicle and verify that each of the gauges functions correctly (you did add coolant, right?). Also, check the illumination, and be sure that the gauges track the dimmer. All should work as planned. Before lowering the vehicle, it is a good idea to check for leaks from the coolant temperature and oil pressure sending units. About two weeks after I completed the installation, I was driving the Mustang and noticed the coolant temperature gauge was abnormally high. I watched the gauge climb past the 220-degree mark, and it kept climbing. The Mustang is equipped with a two-speed fan, and the high speed kicks in at 235 degrees, so I was watching closely. As the gauge hit 235 degrees, it kept going. As it hit 240 degrees, I pulled into the nearest parking lot and shut off the engine. In the 30 seconds it took me to do this, the gauge passed 250 degrees and headed to 260 degrees. Only at this point did the stock gauge begin moving north of its normal position. It went from its typical center-of-the-gauge reading to full scale in about 5 seconds. Gee, that’s useful. Some quick diagnosis in the parking lot revealed that the OEM electric cooling fan had seized up. Thanks to the accuracy of these gauges, I was able to avoid puking coolant all over the road and possibly damaging the engine. Now you understand why I believe aftermarket gauges are a necessity in any performance vehicle!

The finished installation looks very clean.

CHAPTER 4 ELECTRIC FANS I’m pretty active at the local car events in the Phoenix area. I’m one of those guys who listens intently to conversations between fellow hot rodders so that I may learn something. I hear lots of discussion among them about the problems and challenges that they face in keeping their prized possessions running. My Olds has a 6-71 Roots blower sticking out of the hood. I like it because it’s fast, the torque curve is immediate, and I love the sound of a blown engine. At a cruise, it’s always a hit; funny how such old technology continues to draw a crowd. After I answer the typical questions, there’s always one guy who asks, “Does it run hot?” Excellent question, and the answer is, “No.” Most enthusiasts are pleasantly surprised by my answer. Some of the hard-core guys take a quick glance at the temperature gauge; when they see 190, they know I’m not joking. Then, they scope out the radiator, fans, fan shroud, etc. Rest assured, I use the best stuff available to me. In many cases, so do they, but many have problems keeping their vehicles cool in the summer. In fact, several have told me that they can’t drive their vehicle in the summer, because it overheats. After I ask the standard questions of them, I show them how my fans are wired. It takes a bunch of current to keep a big fan running efficiently; it’s a lot more current than most realize. In the case of my fans, I run dual 16-inch Spals, which require, according to the manufacturer, 22 amps of current at 12 VDC to achieve rated CFM. At 14.4 VDC, they require even more. Obviously, a fan of this size can’t be powered off a standard switch, so using the switch to activate a relay is a given. Even better would be a fan controller, but that’s the exception and not the norm.

This 16-inch Spal puller fan requires some big current to spin it. The pigtail on the fan motor has smaller-gauge 14-AWG wire; don’t be misled by this. How do you determine what gauge of wire to use for your fans? Well, a few things determine this:   

Actual continuous current demands of the fan. Distance between the fan and the relay. Distance between the relay and the source of power.

In my Olds, the relays are mounted on the interior side of the firewall to keep them out of the elements as my Olds has no inner fenders. The distance between the relays and the fans plus the distance between the relays and the source of power necessitates 10-AWG power wiring for these connections.

But, that’s just half of the equation. In order for the fans to get the current they require with a minimum of voltage drop, they require a very-low-resistance return path back to the charging system’s negative (– ). In my case, that’s the frame. Overlook either of these and you could be one of the many who struggle to keep their vehicles cool with electric fans. If you’ve relocated your battery to the rear of the vehicle, you likely have further compounded this problem. Of all the things that I discuss with local enthusiasts, this subject is the number-one topic. For an electric-fan-equipped cooling system to operate correctly, it’s a given that you need the correct-size radiator and at least one correct-size electric fan. If space allows, I prefer pullers to pushers, as pulling air through the radiator is a more efficient way to cool it. Finally, the fans need to be mounted to the radiator in such a way that they can effectively do their job. In every case, a fan shroud improves the effectiveness of the fan, electric or not. When I look closely at cooling system components, I look at things differently than most. In most cases, I see very few mechanical problems, such as the ones just mentioned. In fact, I’m pleasantly surprised at the effort most put forth in doing things correctly. So, why do they have problems? Simple. It’s all electrical related. The following play a significant role in how efficiently your electric fans can do their job:  Output capability of the alternator, specifically at idle.  Size of the charge lead from the alternator to the battery.  Size of the power wire from the battery to the vehicle’s electrical system (not to the starter).  Proximity of the battery to the alternator.  Size of the wiring between the source of power for the fans and the fans.  Voltage drop across any switches, relays, or connections between the source of power for the fans and the fans.  Return path from the fans to the charging system’s negative (–).

Have a full-frame vehicle? Then use the frame as the return path for all things electrical. Shown here are the grounds for the electric fans, core support, cylinder heads, and the alternator; all held firmly to the frame by a tapped 5/16-18 bolt.

Wow, there’s a lot to consider here. Remember, all DC electric fans spin faster with more voltage. A faster-spinning fan moves more air (to a point). By optimizing the voltage delivered to the fans, you can optimize the airflow capability. (This is the kind of stuff I look at.) When looking under the hood, the first thing I notice is that the charge lead on a generic alternator is 10 AWG. That simply isn’t big enough to supply enough current to a performance vehicle with a bunch of current- hungry accessories. And who knows how much current that generic alternator can really make at idle at operating temperature? That’s one of the most important factors. (See Chapter 5.) So, where do you start? Simple. The best place to start the process of optimizing the performance of your electric fans is by determining if you have a problem to begin with. Hey, no sense fixing what ain’t broke. Recall what you learned in Project 3 in Chapter 2. This process is identical. Project 6: Evaluating the Performance of Electric Cooling Fans Set up DMM to read DC voltage. Bring vehicle up to operating temperature. The electric fans need to be running before proceeding to Step 3. Connect DMM to alternator and battery. With the vehicle idling at operating temperature, connect the red probe of your digital multimeter to the output stud of the alternator (directly), and connect the black probe to the battery negative (–). Be sure to record this measurement. Connect probes to alternator and electric fan. Now, leave the red probe connected to the output stud of the alternator, and move the black probe to the positive input wire for your electric fans, as in, directly at the fan motor (bypassing all connectors). Record this measurement. Just as in Project 3, the measurements you took in Steps 3 and 4 show you the voltage lost between the alternator and the fans. Consider this as a percentage, and remember what you learned in sidebar “Voltage Drop Calculations” on page 39. If you measure more than 5 percent in Step 4, you have work to do. Chances are good that you measured a bunch more. Okay, maybe you do need a bigger charge lead than 10 AWG, especially if your battery is mounted in the trunk. At the end of the process, you may find that you need a larger alternator (see Chapter 5). The idea here is to get your electric fans working optimally. The objective is to get as much air flowing through your radiator as possible, which promotes cooling.

Take this measurement with the vehicle idling at operating temperature with all of the accessories removed. The 1.80 VDC is the amount of voltage lost from the output stud of the alternator (the source of the highest voltage available) and the fan power lead. That’s 12.3 percent, so this is a huge voltage loss.

So, before you yank off your electric fans and re-install a centrifugal fan, check out Project 7, where I show you how to optimize their performance in a friend’s street/strip car. Project 7: Optimizing the Performance of Electric Cooling Fans

This kit is from Flex-A-Lite. It includes dual 13-inch fans mounted to a plastic fan shroud that has a rubber gasket around the fans. It’s designed to give a good seal to the radiator. Bill Surin is an Olds guy through and through. He rides in my Olds if he has to, but he would really prefer that my car had an Olds engine in it. In my opinion, Bill exemplifies the audience I am targeting with my books. His car is insanely fast; can you say 10s in the quarter-mile? He has the time slips to prove it, and he drives his car to and from the track. Of course, it’s Olds-powered: trusty 455. Bill is very mechanically capable. He builds his own engines, can tune a carburetor like nobody’s business, and his car hooks on the street like few others I’ve ever ridden in. Bill’s shortcoming has always been wiring, but he’s getting better and better at it each day. Be aware that the use of the following information does not overcome mechanical problems that need to be resolved such as lack of a fan shroud, a radiator that is too small, a 30-year-old radiator that is full of gunk, the wrong thermostat, or using 100-percent antifreeze. I have to assume that you’ve been through all that stuff already and have done your very best to sort those things out.

The red wire with the black heat-shrink on the ring terminal (arrow) is the power lead for the fan relay. It is 10 AWG. Instead of buying a complete kit that includes a radiator, electric fans, fan shroud, and a properly sized wiring harness (such as those sold by Ron Davis Racing Products, Be Cool, and others), most enthusiasts buy the parts individually. It is fairly common to retain the stock radiator and add electric fans to it, and numerous companies offer these parts. This is what I see most often. Bill outfitted his Olds with a four-row radiator that he got from a Chevelle (hey, isn’t that a Chevy part?) and a Flex-ALite electric fan/shroud kit with 13-inch-diameter fans. When Bill originally wired his electric fans, he sourced the power for the relay that controlled them at the output stud of the alternator. By doing this, he was able to eliminate the voltage drop through the charge lead (8 AWG) to the rear-located battery and from the battery back forward, but this is not the correct way. You should never tie accessories to the output stud of the alternator, as the voltage regulator works in response to voltage. High-current loads, such as electric fans and pumps, are a definite no-no because they consume a bunch of current when turned on, which causes the regulator to respond. The only load that should be tied to the output stud of the alternator is the one presented by the charge lead connected to the battery. I relocated the source of power for the fan relay to a junction block under the hood (fed from the rear battery) before taking the measurements in Step 3 and Step 4 of Project 3 in Chapter 2, as this would be typical. Let’s fix the problem the correct way. Because you already know what you’re likely to find as a result of reading Project 3, let me point out the obvious:  

The fans require 14 amps of current, each, at 12 VDC. The battery has been relocated to the trunk.

 The charge lead is 8 AWG, which is one size up from 10 AWG. However, it is still too small to supply the vehicle’s accessories with enough current, especially considering that it’s about 18 feet long so that it can reach the bumper-mounted master on/off switch.  The power wiring to the fan relays is too small, as evidenced by how hot it gets.

The battery in the Olds is located in a poor spot, and it chews up a lot of trunk space. The wiring runs through the floor of the trunk through correct-sized rubber grommets to protect it.

This solenoid is used to connect power to the starter only during cranking. I am going to eliminate it so that I can use a single cable to feed both the starter and the Olds accessories.

Before changing anything, I discovered that the large red wire to the fan relay gets super-hot after the vehicle has been driven for a while. Bill recently made the repair shown here, but that didn’t solve the problem. Does any of this sound familiar? Now, let’s talk about the not-so-obvious stuff:  Bill bypassed the solenoid in his starter and uses a remote solenoid in the trunk so that the lead between it and the battery was live only during cranking. Therefore, the 2-AWG cable that runs from the rear to the starter supplies power only to the starter and not to the accessories.  A second 8-AWG wire (also about 20 feet long) runs from the bumper-mounted on/off switch to the driver-side inner fender to supply the vehicle’s accessories with power.  None of the runs of wiring between the front and rear of the vehicle are protected with fusing of any type. (See Chapter 5.) This is a big project, so let’s follow my standard procedure again. Define the Objective Optimize the performance of the electric cooling fans. To do that, you need to minimize voltage drop to them. (This process was shown in great detail in Project 3.) I’m just talking more current here, but the theory is the same. In this case, we are starting with 1.8 volts of drop, as shown in Project 6.

With the vehicle at idle and at operating temperature, and with all of the accessories on, the draw is 67.6 amps of current the way the vehicle is currently wired.

Outline the Considerations Because this is a street/strip car, the battery has been relocated to the trunk for better weight distribution, and an NHRA mandatory on/off switch has been installed on the bumper. In order for the vehicle to pass tech, the on/off switch must function so that a running engine stops running and power to all accessories is disconnected when the switch is turned off. For that to work, the alternator’s charge lead must run to the rear of the vehicle and pass through the on/off switch. (Yes, there is another way to accomplish this but this is the more common way.) Finally, Bill prefers to manually switch the fans on and off, rather than have them come on automatically. (I’ve always preferred automatic switching, but that’s just me.) Before I can list the parts required, I need an idea of how much current is required by the accessories at idle (think sitting at a stop sign). The easiest way to do this is to bring the vehicle to operating temperature, turn all of the accessories on, and measure that. Do this for your vehicle, and record the measurement. Refer to Figure 4.1 to determine the correct gauge of cables required to suit your needs based on the current requirements and cable length. Finally, you need a convenient place under the hood of the vehicle to be a source of power for all of the vehicle’s accessories, including the ignition switch and OEM fuse panel.

Figure 4.1.

Figure 4.2. Create a Diagram A diagram helps you to determine the correct wire, terminals, relays, and associated accessories to complete this job. Figure 4.2 is for manual switching, as in Bill’s car. Chapter 5 provides, in great detail, all of the steps involved in relocating your battery to the trunk; it also provides information for you to determine how to upgrade your alternator. Therefore, those things are only briefly discussed in this chapter. List the Parts Required There really is no magic here. You need to select the gauge of wire that corresponds with your needs, obtain the associated terminals and connectors, and protect the parts accordingly. This project requires the following parts:       

JL Audio 1/0-, 2-, and 8-AWG power and ground wire 1/0-, 2-, and 8-AWG ring terminals (1) Rockford Fosgate RFD4 power distribution block (2) Hella 40-amp waterproof relays (2) Waterproof relay sockets Miscellaneous electrical terminals Miscellaneous hardware, such as rubber-lined metal clamps and split-loom tubing

Upgrade the charge lead. In this case, the car requires 2-AWG wire. Yes, 2 AWG! Remember, the battery is merely an accessory when the vehicle is running, and it takes between 7 and 10 amps of current just to maintain a surface charge on it. So, you’re really only concerned with the run from the alternator to the accessories, and that happens to be a very long run in this car, because of the rear-mounted on/off switch; it’s 18 feet to the on/off switch and another 8 feet to the battery. You also have to take the size of the alternator into consideration when making this determination, and it is (reportedly) a 140-amp unit.

I moved the battery to the passenger’s rear side of the trunk. This puts it out of the way and offers excellent weight distribution. Note how neatly the wiring is tied and anchored to keep it out of the way. The battery’s ground cable is bolted directly underneath to the frame rail. I also ran 1/0-AWG wire from the battery to the front of the car, as I suspected the accessories were being starved for current, giving us an artificially low reading, due to the undersized cables used. Because I do not want to add more weight than necessary to the car, I removed the rear-mounted starter solenoid, so that I could eliminate a cable run between the front and rear and use the 1/0-AWG cable to feed both the accessories and the starter.

All wiring passes through these OEM plugs in the floor. I used a 1-inch snap bushing here to protect the wiring.

Shown here are the connections to the rear-mounted on/off switch. I used plastic split-loom tubing to protect the wiring as it passes over the frame rail. Note all the rubber left over from burnouts! Install distribution block. As discussed, you need a convenient place in the front of the vehicle to distribute power. I prefer not to use the stud of the starter for this purpose, as GM typically did. A distribution block provides an excellent way to distribute power between the starter, the ignition switch and OEM fuse panel, and the aftermarket accessories.

The 1/0-AWG cable from the on/off switch terminates here at a Rockford Fosgate RFD4 distribution block. This unit splits power to the starter and accessories. For now, I will be re-using the smaller power point that Bill previously installed. I used the DMM (not shown) to validate the work.

Before touching the fan wiring, I took a second voltage drop measurement to measure the effectiveness of the charging system upgrades. This resulted in more than 1 VDC of improvement. This illustrates how big a role this plays in solving a problem like this. Prepare fans. If your fans are stock, they likely have the correct connectors terminated on them. Bill had cut them off when he originally installed the fans.

These high-current connectors are available from www.ceautoelectricsupply.com. You need a U-barrel crimping tool to install them. Shown here are the male pins and female body. Crimp the terminal on the wire using the correct tool.

The wires and terminals slip into the plugs. Your finished work will look something like this. Remove existing relay.

Closer inspection of the wiring in this relay socket shows damage from heat. This socket is pre-built with 14-AWG wiring and is simply not up to the task of supplying power to two 14-amp fans. Pre-mount fan relays.

So that I can minimize the voltage drop to the fans, I’m using a pair of Hella 40-amp weatherproof relays, one for each fan. When installing relays under the hood, it is best to use weatherproof relays, which require matching sockets. The seal between the socket and the relay combines to make the entire assembly weatherproof. You can purchase the sockets pre-assembled (with 12-AWG wiring), or you can buy the parts and assemble them yourself, which is what I did here.

I found a nice area in the driver-side fenderwell to mount the components. I fabricated this piece of 3/16-inch ABS plastic to accommodate one fuse block and four weatherproof relays. Select a suitable location to mount the relays. When installing relays in the engine compartment, always mount them so that the wires point downward. Wire relay sockets. I’m using 10-AWG wiring for the fan relays, which is why I’m making up my own sockets. This is really quite easy.

Assembling these sockets is easy with a U-barrel crimping tool. The terminals are a Metri-Pack variety, and they slide into the socket from above (exactly opposite of standard relay sockets).

Once you have wired the relay socket, slide on the seal from the bottom. This is a bit tedious when using 10-AWG wires for the switch of the relay.

Assemble as much of this stuff on the bench as you can. It makes the job of installing it in the vehicle much easier. Shown here is a six-position ATC fuse panel that you can get from www.ceautoelectricsupply.com; it provides protection for the fan relays, etc. Mount relays in vehicle.

Mount the assembly in the vehicle. The mounting studs serve a second purpose, as they provide anchor points for the stock underhood wiring harness.

Optimize return path. You can’t simply ground the fans with a screw and call it done. Rather, you have to consider the overall resistance between the ground you choose for the fans and the charging system. Fortunately, this Olds has a full frame under it, and this is an ideal return path.

As is typical of these early A-Bodies, I located two holes in the frame rail and tapped one to accept a 5/16-18 bolt. I ran an 8-AWG jumper from the frame to the core support to use as a grounding point for the fans via a 1/4-20 bolt. As always, remove the paint, and use plenty of white lithium grease and star washers to ensure solid electrical connections. Ground fans.

Ground the fans to this bolt. This is far better than using a self-tapping screw. Connect fans.

Here is the assembled harness to each fan, each terminated with female pins and male bodies. These plug right in and offer an excellent connection.

The finished installation is nice and clean. The fuse panel connects to the Rockford Fosgate distribution block via a piece of 8-AWG cable. I connected a few of the accessories to this fuse panel. Check your work.

Now that the work is done, you need to take the same measurements you took at the beginning of this chapter.   

Measure the voltage at idle at operating temperature (as you did in Step 3 of Project 6). Measure the voltage drop across the fan circuit (as you did in Step 4 of Project 6). Measure the overall current draw of all accessories.

Evaluate your results. Now that you have the data, it’s time to analyze it. Before you call it a day and pat yourself on the back for a job well done, let’s compare these numbers. Write your numbers in the chart below.

Think that an 8-AWG charge lead was big enough? Guess again. This clearly shows that the 8-AWG wiring was inadequate, as the accessories now require 87 amps of current at engine idle and operating temperature, an increase of nearly 20 amps.

Interestingly enough, I also made the following measurements of the fans before and after that I don’t illustrate:

Bill was amazed at the results, but it simply illustrates that the fans were choked for current before. Now that we have corrected the wiring, the fans can gulp as much current as they like. This allows them to work as efficiently as possible. Summary By now, you know that minimizing voltage drop is the key to improving performance of accessories, such as current-hungry lights, fans, and pumps. Project 7 and Project 3 provide you with two examples of resolving these problems the correct way without guessing. If, on the other hand, you are installing things from scratch, no problem.

CHAPTER 5 HIGH-PERFORMANCE CHARGING SYSTEMS In Chapter 4, I touch on the importance of choosing the correct-size alternator. (In Chapters 5, 6, and 8 of Automotive Wiring and Electrical Systems, I discuss the charging system in great detail, including the alternator, the return path, and the battery.) The alternator is the source of power for all of the vehicle’s accessories (including the battery) when the engine is running. The fact of the matter is that your charging system’s state of health determines how well the accessories you install in your vehicle function. This chapter includes three projects that are designed to take the guesswork out of the equation. Project 8: Determining Alternator Output Your vehicle has an alternator. Is it the correct one for the job? How do you determine if you need a larger alternator? How do you know which one is best for your application? Is a one-wire option the solution? All good questions; by the end of this project, you’ll know the answers. You need these specialized tools:  

High-quality digital multimeter (preferably two) Current clamp that is capable of measuring at least 200 amps.

The objective here is simple: to determine if the alternator presently installed on your vehicle is suitable for the task at hand. Like many hot rods, my Olds is currently equipped with a single-wire aftermarket alternator. After the vehicle has reached operating temperature and the electric fans kick on, the fun begins. Specifically, when I come to a stop, the volt meter drops from just over 14 VDC to just over 12 VDC; this is a pretty significant swing. So, why is that? Is it because it’s a single-wire design? Let’s find out. The specification sheet that was provided with this alternator shows that it is capable of 96 amps output at idle. (Idle is generally defined as 800 engine RPM and 2,400 alternator RPM as the alternator typically spins three times for every one crank revolution.) This amount should be more than adequate to power all of the accessories in my Olds, but is it?

My Olds is currently equipped with a 140-amp single-wire alternator. A 4-AWG charge lead runs from it to the rear-mounted batteries. It also has a 4-AWG ground wire between its case and the frame.

Determine current requirement of accessories. Bring the vehicle to operating temperature and turn on all of the accessories (headlights, etc.) before taking any measurements. Install the current clamp around all wires connected to the charge stud, within 12 inches of the alternator, the closer the better. Take this measurement at idle.

This is excellent data to form a starting point. Note the voltage with all of the accessories turned on and the vehicle running at operating temperature. When the vehicle is at operating temperature, I determined that my Olds requires 57 amps of current to power all of the accessories at idle. This is an excellent starting point to determine whether the existing alternator provides enough current. I also measured 12.70 VDC at the same time. This is an indication that the alternator is struggling to keep up at idle. Let’s verify this. Measure alternator’s output at idle. This is a job for a very specialized tool, a charging system analyzer. Of course you don’t have one of these in your garage, but well-equipped auto service facilities do. The Snap-on MT3750 AVR, used in this example, features an internal 500-amp carbon pile load and is perfect for loading even the biggest of alternators. The following procedures are specific to the Snap-on AVR analyzers, but others are similar. (Refer to the operating instructions provided with your particular unit for specifics.) A. Connect the analyzer. This is simple; the power and ground leads clamp to the respective battery posts, and a current clamp is placed around the charge lead as close to the alternator as possible with the arrow pointing away from the alternator. That’s it. B. Zero the display on the unit. C. Start the vehicle and bring the engine to operating temperature. Remember, you’re only concerned with output at idle at operating temperature. D. Turn off any accessories that you are able to in an effort to get the most accurate measurement. E. Using the LOAD knob, slowly introduce the load to the alternator until the voltage measures 12.0 VDC on the display.

The Snap-on AVR charging system analyzers are incredibly powerful tools for diagnosing charging systems and even starters. The MT3750 AVR has a built-in 500-amp carbon pile load, applied variably by the knob at the right, and it can quickly load-test alternators and batteries. This machine doesn’t lie. I did three load tests within about a minute of each other to let the internal load cool. A measurement of 63 amps at idle was consistent within 2 amps for each reading. On a vehicle equipped with a rear-mounted battery, place the current clamp around the charge lead in the rear. Some voltage drop naturally occurs over the run of the cable, which results in a slightly lower current measurement. This is reflective of real-world conditions, so it is excellent data. As you can see, 63 amps leaves only 6 amps of headroom over the requirement of the accessories at idle. The EFI fuel pump I’ve selected requires up to 30 amps, which is significantly more than the pump I’m using currently. The Olds needs an alternator with greater output at idle, plain and simple; there is no avoiding it. The telltale sign is the activity shown on the dash-mounted volt meter. The display shows over 14 volts when cruising and just over 12 volts at a stop sign. Steps 1 and 2 simply validate that. Determine correct path to upgrade. Every alternator company prefers to talk to you on the phone rather than have you click “Buy It Now” on their website. This allows their staff to guide you toward purchasing the correct product for your application. You wouldn’t order a camshaft that way, would you? The alternator is the brains of the charging system, so it’s best to get the correct one the first time around. When you contact a company about buying an alternator, the staff will have a host of questions for you. You now have the data to answer them correctly, thereby removing the guesswork from the process. Any alternator company worth its salt focuses on your current requirements at idle. If the employees only discuss maximum output numbers, contact another company. With your brand-new alternator in hand, follow along as I show you the correct way to install it. Project 9: Upgrading the Alternator

These GM large-case alternators from Iraggi Alternator are shown from the rear: AD-244 (left) and CS-244 (right). Both are three-wire design. Although both units have the exact same stator and rotor poles, the unit on the left offers several benefits; an internal fan is the most obvious. The AD-244 features a much more modern regulator design. Yes, even a vehicle equipped with a 140-amp alternator and a 4-AWG charge lead can benefit from an upgrade. I assume you are starting with less. Either way, the process is the same. These are the components you need:      

Iraggi Alternator AD-244 alternator JL Audio 1/0-AWG power and ground wire Rockford Fosgate RFFANL fuse holder (1) 250-amp ANL fuse (1) 1/0-AWG alternator boot Associated terminals and connectors

I prefer a three-wire alternator over a one-wire alternator for numerous reasons, the most important being that it is switched on when the key is in the IGN position. A one-wire unit requires that the alternator reaches a certain engine speed before it begins to charge, typically more than 1,200 rpm. No, a three-wire alternator isn’t any harder to install; it’s actually quite simple. I’m using the newer-style Iraggi alternator unit on my installation because it’s simply gorgeous, and it mounts right up to my existing bracket no differently than the CS-style unit would. Both are rated at 220 amps maximum and 175 amps at idle. No sense in messing around when you’re upgrading! Given the alternator’s current output capabilities and the fact that the battery is in the rear of my Olds (18 feet of wire, to be exact), this installation requires that I upgrade the charge lead from 4 AWG to 1/0 AWG. Yes, that’s 1/0 AWG. Mount alternator. As shown, the AD-244 fits right into the alternator bracket I fabbed up for the CS series. For illustration purposes, I left the 4-AWG charge lead, as well as the 4-AWG ground lead to the frame, for now.

Whodathunkit? This brand-new, modern alternator fits perfectly to the bracket I fabricated for a smallcase CS design. Did I mention that this thing is gorgeous? Wire ignition input to regulator harness. If your vehicle is already equipped with a three-wire alternator, you simply need to connect the dashlamp circuit only to the new regulator harness. My Olds does not have such a harness; no problem. A. Run a wire from the regulator harness to the fuse panel inside the vehicle.

B. Solder this to the dash lamp input of the regulator.

Slip the PowerBraid over the single 18-AWG wire (not shown). I used the same color as that of the dash-lamp input to the regulator. Be sure to slide your heat-shrink tubing on the wire before soldering. C. Insulate this connection with heat-shrink tubing.

Heat-shrink the connection, and then finish covering it with PowerBraid. Connect to fuse panel. The stock dash, instrument cluster, and alternator idiot light in my Olds are long gone. Therefore, it’s necessary to instead use a 1/2-watt 47W resistor to reduce the input voltage to the regulator.

Cover the resistor leads with short lengths of insulation from 18-AWG primary wire. Crimp a butt connector on either end in preparation for installation.

Install the resistor in the passenger compartment to keep it away from the heat of the engine and exhaust. Connect the other end to a fused, switched, ignition output of the fuse panel. Make up new charge lead. Given the size of alternator you are using, your charge lead may be 2 AWG, or even 4 AWG. I can’t stress this enough: Follow the manufacturer’s recommendation exactly or refer to Figure 4.1 in Chapter 4 to determine the correct gauge of wire. Using a smaller-than-required charge lead is the number-one mistake most enthusiasts make when installing a high-output alternator.

A. Slide the correct-size ring terminal on the end of the cable and insert the assembly into the crimp press. B. Beginning at the cable end of the terminal, make at least three crimps side by side to hold the terminal securely to the cable.

If you make up a number of large-gauge cables at a time as I do, the proper crimping tool makes short work of the process. This JL Audio 1/0-AWG cable is super flexible and exceeds the AWG specification. Choose the correct die, and insert the terminal in the tool as shown to make the crimp. C. Your finished termination should look like the one below. If you do not have access to a crimp press, you can use a hammer crimp tool, or you can even solder the terminal to the cable with a propane torch.

Each JL Audio ring terminal has a very long ferrule. The ferrule permits multiple crimps to ensure an incredibly solid connection. Each terminal also has a small opening at the end, which makes it easy to solder it, if you prefer. Install charge lead.

Connect the charge lead from the alternator output post to the battery positive (+) terminal. If you have a rear-mounted battery, you have to route the charge lead to the rear of the vehicle accordingly. (Refer to Figure 5.5 for specifics.)

You can see the scale of this cable. Yes, it is massive, but it is super flexible and easy to route. Use the correct-size alternator boot (available at www.ceautoelectricsupply.com), connect the cable to the alternator’s output stud, and use wire ties to keep the cable away from moving parts and heat sources. Upgrade return path of alternator. As my Olds sits on a full frame, I’ve used it as the return path for all things electrical. Even if your vehicle is of unit-body construction with separate frames front and rear, I still find that the frame rails make excellent connection points for the charging system ground leads, especially when sub-frame connectors are present.

I upgraded the 4-AWG ground lead from the alternator to a 1/0-AWG ground lead. Always use white lithium grease and a star washer for such connections.

I bolted everything back in place. Use 5/16-inch or 3/8-inch bolts for all return path connections to the frame rails. Use the following procedure to ensure excellent electrical connections that hold up to the elements. A. B. C. D. E. F. G.

Remove the paint from the metal with a die grinder to expose the bare metal. Try to use an existing hole so that you can avoid drilling into the frame rail. Drill the hole to the correct size of your bolt and ring terminal. Tap it accordingly. Use a liberal amount of white lithium grease on the bare metal. Use star washers between the metal and ring terminals. Tighten these bolts with a long-handled ratchet.

Upgrade return path of battery. Your battery likely has a single, large, 4-AWG cable that connects to the engine block. This is the return path for the stock alternator and starter. Connect the battery to the frame rail with the same size cable you ran from the case of the alternator to the frame rail. For a front-mounted battery, this is in the same location. For a rear-mounted battery, this is to the frame rail on the same side of the vehicle to which the alternator is grounded.

This is the correct procedure for vehicles with rearmounted batteries. Ground the rear battery(ies) to the same frame rail that the alternator’s ground wire connects to. I should note that this vehicle is backhalved.

This is the correct procedure for vehicles with the battery located under the hood. Ground the battery and the alternator to the same frame rail. Fuse charge lead near battery. This procedure is for a rear-mounted battery only. If your battery is located under the hood, a fuse is not required between the output of the alternator and the battery positive (+) terminal. If you are worried about the voltage regulator failing and causing voltage runaway, you can certainly install an in-line fuse that is slightly larger than the maximum output of the alternator.

I mounted the fuse holder to the sheet metal with self-tapping screws. ANL fuse holders and fuses are really the best choice in such applications. Because I used aftermarket battery clamps when I installed the batteries originally, I had an extra 1/0-AWG connection point. This made it simple to connect the charge lead. For vehicles with a rear-mounted battery, the charge lead must be protected near the battery. This is to protect the run of wiring along the length of the vehicle in the event of an accident. The complete process is illustrated in Project 10.

This Rockford Fosgate fuse holder and battery clamps have smash-wire- with-screw (SWWS) set screws to secure the cable. Use some blue thread locker on these kinds of set screws to keep them from backing out. Tighten these screws with an appropriate Allen wrench. Install fuse in fuse holder. Well, how did I do? I’ll let the photos in this step tell the story. How is that for a substantial improvement? Admittedly, a 220-amp alternator is a tad overkill for this application, but I can guarantee that I won’t have charging system problems, and I won’t have fuel delivery issues due to voltage drop. This alternator will be perfect to keep my EFI fuel pump happy with enough current at high engine speeds, which is critical for a blown, injected engine! I did test the Iraggi unit with the 4-AWG wiring. Unfortunately, I didn’t take a picture and realized this after the wiring was upgraded. I measured 118 amps at 12.1 VDC at operating temperature with the Snap-on analyzer. That’s a substantial improvement over the alternator I removed, but as you can see, that’s nowhere near the Iraggi’s full potential. This is proof; indeed, that the correct-size charge cable is a must, and it resulted in a 56-percent gain in output at idle in this project!

Wow, 184 amps at idle (approximately 800 engine rpm). This Iraggi unit makes nearly three times as much at idle as the unit it replaced. This exceeds Iraggi’s specifications, even with approximately 18 feet of cable between the alternator and the rear-mounted batteries. The correct-size cable is a must if you want to get all of the performance that such an alternator is capable of.

Unfortunately, it’s not possible to do a direct comparison between these numbers and the ones shown above because I upgraded the charge lead at the same time as I did the EFI conversion. The EFI installation included a much larger fuel pump and a current-hungry ECU in the process. The takeaway here would be that the voltage sits nicely above 14 VDC at idle at operating temperature with all accessories on. They draw more than 91 amps of current collectively. Project 10: Relocating the Battery to the Trunk

This 1967 Nova is a no-expense-spared build. It’s a full-tube chassis car with more than 1,350 hp on tap, thanks to the 10-71-blown 555-ci big- block Chevy. This project should be simple enough, right? I mean, you can’t turn around without it bumping into an aftermarket battery relocation kit. Guess what? If you drive your vehicle on the street, every one of these kits falls short of what you really need: the proper protection.

Like many drag racers, Motor Mike chose a pair of Optima YellowTop batteries for his car. YellowTops are really not suitable for street use, as they take a significantly higher voltage to keep a surface charge on them. They are ideal for competition use, though, as they can be recharged between rounds and hold up well to deep cycling. He fabricated the mounting brackets. Occasionally, I’m called to work on a really nice vehicle. Motor Mike’s 1967 Chevy II Nova is the nicest vehicle I’ve ever worked on, so it’s a real pleasure to include it here. Even though it’s built for 7second quarter-mile passes, Motor Mike likes to occasionally take it out on the street. This vehicle includes numerous current-hungry accessories:      

Dual 13-inch Spal electric fans, 20 amps continuous each Aeromotive Eliminator fuel pump, 30 amps continuous Meziere 55-gph coolant pump, 20 amps continuous Meziere 55-gph remote coolant pump (for the intercooler), 20 amps continuous MSD 8 Series ignition, 21 amps at 7,000 rpm Dual Optima yellow-top batteries, 10 amps each to maintain surface charge

All in all, this is the perfect vehicle to illustrate how to safely wire a rear-mounted battery. You already know the objective, so let’s outline the considerations. Mike’s Nova sits on a full tube chassis. The alternator (a 180-amp unit) is mounted to the driver’s side of the engine. Finally, this vehicle also has a rear-mounted NHRA mandatory on/off switch to kill all power to the vehicle in the event of an emergency.

Figure 5.5. List the Parts Required This project requires the following parts:          

JL Audio 1/0-, 2-, 4-, and 8-AWG power and ground cable 1/0-, 2-, and 8-AWG ring terminals (2) Rockford Fosgate CB-200 200-amp circuit breakers JL Audio XB-MFBU-ANL fuse holder (2) military-style positive battery clamps (2) military-style negative battery clamps (1) JL Audio XB-MGLU master ground lug (1) Rockford Fosgate RFD1 distribution block Miscellaneous electrical terminals Miscellaneous hardware, including rubber-lined metal clamps and PowerBraid loom

Create a Diagram Refer to Figure 5.5. Note the protection for all of the large-gauge cables; protection that, in my opinion, is not optional for any street-driven vehicle. Let me explain: If your vehicle is involved in an accident, and either of the cables between the battery and the front of the vehicle is shorted to the frame or chassis in the process, this short circuit could cause the rear battery to explode. That’s not a good thing, considering its proximity to the fuel cell. Determine logistics of installation. Yeah, you have to plan a bit before you start cutting cable. Before helping Mike with the project, he welded numerous 3/8-inch bolts to the chassis: one near the batteries, one near the tin that would hold the ignition system and fuse panels, one behind the instrument panel, one alongside the transmission

tunnel, one behind the bumper inside the front clip (totally removable clip), and one along the passenger’s side of the engine. These bolts provide excellent low-resistance connection points for all of the accessories and an excellent point of commonality between them and the charging system. Great idea! In addition, Mike planned to run all of the cables alongside the frame rails underneath the body.

When you’re building a vehicle from scratch, you may take many liberties. Motor Mike welded 3/8-inch bolts to numerous points on the frame, thereby creating an extremely simple way of connecting all electrical grounds to it. This is an excellent idea for a tube-chassis vehicle, and it worked flawlessly. Temporarily install battery clamps. I use military-style battery clamps here. These are readily available at battery supply and service centers, as well as at marine resellers. I like them because you can easily connect multiple large cables to them.

These military-style battery clamps are perfect for this installation. Motor Mike colored in the + and – markings on the battery to avoid accidental reversal of the cables from a charger in the pits. Very smart. The idea here is to choose the best orientation of the clamps so that you can begin fabricating the cables.

Make ground cables for batteries. As you can see, I use the crimp press a lot.

I am using a little different lug here, the more commonly available “mega lug.” These are readily available from battery supply centers, but they require the appropriate crimp tool to install them.

The ferrule on mega lugs is long enough to get three solid crimps. This is a 3/8-inch lug, but they are also available in no. 10, 1/4 inch, 5/16 inch, and 1/2 inch.

This is the completed cable that will connect the battery negatives (–).

Here is the completed cable that connects the battery negatives (–) to the frame. I used super-thick, adhesive-lined heat-shrink tubing to insulate the connections. Temporarily install ground cables.

A perfect fit. Notice how well these battery clamps work. After trial fitting, remove the ground wire from the chassis. Mount circuit breakers. The objective of the circuit breakers is to protect the run of 1/0-AWG cable, as it runs from the rear of the vehicle to the front. I use dual 200-amp breakers in parallel for this purpose; the paralleled pair opens in the event of a short, but isn’t fazed by even the highest-torque starters. Mike fabricated a clever mount for the circuit breakers that mounted perfectly to his custom battery hold-down bracket.

Mike started with a scrap piece of 1/8-inch-thick steel stock.

The bolt hole at the top allows this bracket to easily mount to the existing battery hold-down bracket.

Another perfect fit.

Make and install power cables for batteries.

These military-style battery clamps offer unmatched versatility, as you can remove and reverse the bolts for the cables and the hold-down for any number of configurations. Make cables for circuit breakers.

The 4-AWG cable is sufficient to parallel the breakers, due to their close proximity to each other. Connect circuit breakers to batteries.

The 1/0-AWG cable goes from the battery to the circuit breakers. Make cable to connect circuit breakers to on/off switch.

The cable between the circuit breakers and on/off switch is 1/0 AWG. I modified the lug slightly with a band saw so that it would fit the breaker. Connect circuit breakers to on/off switch.

The finished circuit breaker installation should look something like this. Determine location for ANL fuse holder. The ANL fuse holder protects the charge lead. A steel panel just forward of the battery was fabricated to locate the charge lead fuse holder. I used a JL Audio XB-MFBU-ANL fuse holder for this purpose. It accommodates wire between 4 AWG and 1/0 AWG, and the wire can enter each end of the fuse holder in one of three directions: straight in or at 90 degrees from either the top or bottom. This provides flexibility. (This panel also provides mounting locations for the rear fuse panel and the relays for the fuel pump, coolant pump for the intercooler, and transmission cooler fan. Because this panel was welded to the support tubing of the frame, I also located a JL Audio XB-MGLU master ground lug here. This provides an excellent grounding point for the pumps and relays.)

Being able to fabricate your own panels is super handy for a project like this. This solidsteel mounting surface provides an excellent home to numerous items, including the charging system fuse holder (bottom right).

Route cables. This is everyone’s favorite part: getting under the vehicle and routing cables. Take your time here. The charge lead routes directly along the frame rail on the driver’s side to the alternator. The main power feed from the batteries to the starter and fuse panels routes along the frame rail on the passenger’s side to a distribution block in the front of the vehicle.

I covered the charge lead and main power feed cables with Techflex braided loom. As usual, these cables pass through the steel barrier with rubber grommets to protect them.

The charge lead (JL Audio 2-AWG cable) connects to the fuse holder and then continues to the on/off switch. I used thinner-wall, adhesive-lined heat-shrink tubing to give these terminations a clean look. Use a dab of blue thread locker on the set screws of these cables, and tighten them very securely.

The cables are anchored to the frame tubes with rubber-lined metal clamps.

Liberal use of clamps helps to keep the cables away from heat sources and moving parts. They are anchored to the frame tubes with self-tapping screws.

You don’t need a lift to make this job easy. Spend a few hours to build some 2 × 4 supports like those shown here, and you’re time ahead with a job like this. And, yes, those massive BLP Dominators sitting atop a Littlefield 10-71 on top of a chiller from The Blower Shop are killer eye candy!

Connect on/off switch. The on/off switch has 3/8-inch studs that are long enough so multiple large-gauge cables and lock washers can be installed on each stud. Connect it per Figure 5.5.

The on/off switch is mounted in the back-up lamp housing on the passenger’s side. Be sure all connections to it are tightened securely and per Figure 5.5, so that it functions per NHRA rules. Connect charge lead to alternator. This fully polished 180-amp East Coast Auto Electric unit is rated to deliver 120 amps at idle (a bit less than what I outlined). Keep in mind that this is a race car that sees occasional street use, so some of the accessories are only used when racing, and the batteries are topped off between rounds with a charger. Motor Mike fabricated a custom alternator mount, which is attached to the lower frame rail on the driver’s side.

The East Coast Auto Electric alternator is mounted so that it spins in reverse. This does not affect its operation. The 2-AWG charge lead connects to it, and the electrical connection is protected with an alternator boot.

Ground alternator. Isn’t that overkill here? After all, the alternator mounts nearly directly to the frame rail. Well, consider that its case is polished and its frame is powder-coated, which is certainly not ideal for conductivity. The ground cable should always be at least the same size as the charge lead. I used a short length of JL Audio 2-AWG wire for this.

I connected a short 2-AWG ground wire to the rear of the alternator via an existing threaded hole. Most alternators have these. Use a star washer between the lug and alternator housing.

Remove the powder coating (or paint) with a die grinder to get to the bare metal.

Apply a liberal amount of white lithium grease to ensure a good electrical connection and to keep the metal from rusting.

Connect the ground wire from the case of the alternator to this point. Use a star washer between the lug and frame to ensure an excellent bite into the metal. Tighten this very securely. Connect power feed. In this step, the power feed is connected to the front-mounted distribution block. As mentioned in Chapter 4, I prefer not to use the stud on the starter as a power distribution block, especially not for an installation like this. Rather, a purpose-made distribution block is ideal for this function. I used a Rockford Fosgate RFD1 to split the 1/0-AWG cable to feed the starter, primary fuse panels, and main switch console (located overhead).

Lots of products from the car audio industry lend themselves to this kind of work. This Rockford Fosgate RFD1 splits the 1/0-AWG feed from the rear-mounted batteries to feed power to the starter, two auxiliary fuse panels, and the overhead switch panel.

This in-line fuse holder protects the 6-AWG power feed to the overhead switch panel. It has a 60-amp fuse installed in it. Connect starter, main fuse panels, and overhead switch console.

Motor Mike chose a switch panel from ARC for the Nova. As I modified it slightly for his use, he repainted the face and re-labeled each of the buttons accordingly. Test your work. If you have a rear-mounted on/off switch, you must verify that it is working correctly before taking it to the track. With the engine running, turn it to the off position. If the engine dies and the power to all accessories is disconnected, you wired it correctly. If the engine continues to run, I recommend that you

verify that the charge lead is hooked to the correct side of the on/off switch. The charge lead connects to the battery side and not the load side. Summary At this point, the charging system is completely and safely wired. As of this writing, Motor Mike is making his test passes in the vehicle in an effort to get his NHRA license. He couldn’t be happier with the way that the charging system has performed. This project was a true pleasure. The wiring in this vehicle exemplifies the difference between just getting it done and creating something that is functional, serviceable, and appealing to the eye. Sure, this is a cost-is-no-object build, but if you take your time, your weekend warrior will come out equally as good.

Some careful planning in the design process makes this tin super easy to wire and to service. Motor Mike fabricated this piece from scratch to fit directly in the front of the passenger’s foot well. I especially like the way he made the bracket for the relays to allow the passage of wiring behind it.

I wired most of this on the bench, and then finished the wiring in the vehicle. Note the temporary labels on the relays to keep things in order as I pre-wire the assembly.

The finished rear panel in the trunk: neat and orderly. Those big AN lines are from the coolant pump for the chiller.

CHAPTER 6 AFTERMARKET WIRING HARNESS At some point, nearly every car guy is faced with the decision of using an existing wiring harness or installing an aftermarket wiring harness. There are many reasons to consider a new harness. However, installing a harness is a big project. Several companies offer wiring harnesses for vehicles of all types. If you are shopping for a replacement harness so that you can simply update an old, brittle, or hacked-up harness in your muscle car, it is a fairly straightforward job. Year One offers reproduction wiring harnesses for many popular GM cars and trucks (Mopar A-, B-, and E-bodies) and Ford Mustangs. American Autowire also offers reproduction harnesses for popular GM vehicles and trucks in its Factory Fit line. Both companies’ products are designed from the original factory blueprints, so they typically install exactly like factory harnesses, and they have original, factory-style terminals. Well, what if you don’t need an OEM-style harness? What if your project car is going to be a street machine with lots of aftermarket electronics? This is where the fun begins when you are in the market for an aftermarket wiring harness. There are many options, and there is no one-size-fits-all solution that I’m aware of. Before you start, I suggest that you answer these questions: How many circuits do you require? What aftermarket electronics will you be adding? Will any of those electronics, such as electric fan(s), electric fuel pump, electric coolant pump, high-powered audio system, off-road lighting, A/C power inverters, etc., require high current? Keep in mind that you always want a bit of room for expansion. There is no sense going to the trouble of installing an aftermarket wiring harness that barely covers your needs. If you’re unsure how to answer the previous questions, you’re best served by contacting the customer service department at any of the major aftermarket wiring harness suppliers and asking their advice. After all, they absolutely want to sell you the product you need to suit your needs perfectly, and this is their field of expertise. Two different types of aftermarket wiring harnesses are currently available. They include the traditional type (such as the Painless Performance Products kit in Project 11) and an all-new breed, which is a multiplex wiring harness (currently, only ISIS Power Products offers this). This chapter covers a traditional harness installation using a kit from Painless Performance Products. Project 11: Installing a Traditional Aftermarket Wiring Harness I selected this vehicle for very specific reasons:  No plug-and-play harness is available for this application.  It requires the use of a universal (one-size-fits-all 1948-and-newer Studebaker) wiring harness.  The owner wants a car that is capable of 9-second time slips and includes many of the conveniences of a modern vehicle.  It has a fiberglass body.

The subject? A brand-new 1941 Willys coupe kit vehicle. Specifically, this is an Antique & Collectible Autos, Inc., fiberglass body sitting on a Fast Times Rods, Inc., frame. Mike has big plans for the vehicle, but he wisely decided to get the electrical work done first. At my suggestion, he installed all of the sound-deadening material in the interior before I took delivery of the car for the electrical work. He chose products from Second Skin. Now, a project like this requires a tremendous amount of thought on the front end so that it can be completed in any kind of time frame. I would say that this is the most difficult project in this book. That doesn’t mean that the products are difficult or confusing to install; they aren’t. It means that it requires a great deal of integration among products by numerous manufacturers to achieve the desired results. This requires substantial planning before the actual work begins. Define the Objective When I first met the owner, Mike Cote, to look at the car, he didn’t know what was and wasn’t possible. During our conversation, he mentioned the following:  Air conditioning will be installed at a later date.  Flaming River steering column, which includes ignition, turn signal, headlight dimmer, and horn switches, will be installed at a later date.  Small-block or big-block Chevy engine with an 8-71 blower to get those 9-second time slips (it would be carbureted) is planned.  Mechanical coolant pump cools this engine.  Aluminum radiator with a single 16-inch electric fan was already installed.  Traditional halogen headlights were already installed. And he had a list of things he wanted or didn’t want to have in the vehicle:  Locate the main fuse panel and battery in the rear.  Install door poppers and electric windows only. (Door locks really aren’t necessary here, as the doors will remain smooth, and no interior components will be installed to lock/unlock the doors.)  Install battery connectors under the vehicle to allow jumping the vehicle and opening the doors electronically if the battery dies with the windows up.  Keep wiring harnesses hidden between the body and doors; he had his mind made up that he wanted to use doorjamb pin and contactor plates.  Pin switches will not be used to activate the interior lights to keep things clean.  No back-up lamps or windshield wipers.

 Possibly upgrade electric fuel pump that came mounted on the frame rail to a larger unit.  Install a high-output ignition capable of firing such an engine.  Install an audio system with two power amplifiers, front and rear speakers, and a subwoofer or two.  Install all buttons and switches (all custom billet), except the ignition, headlight, headlight dimmer, and turn signal switches, in a yet-to-be-constructed center console.  Install wiring to accommodate remote fan-cooled oil and transmission coolers behind each front wheel.  Install some kind of smart fan controller to control the electric fan.  Locate all front-mounted components on the driver’s side behind the cluster and above the column to keep them hidden; he provided an aluminum mounting plate to accomplish this.  Conceal underhood wiring when possible.  Entire installation needs to be easily accessible for hassle-free serviceability. In addition, he wanted the following:  Install electric trunk opener via a console-mounted switch and the keyless entry system (trunk latch assembly with a built-in actuator that had been purchased from Fast Times Rods).  Use keyless entry system to open the doors.  Install trunk lights that are activated automatically as the trunk is opened, but with a master on/off switch that could be used to disable them at a show during the daytime.  Install a motorized license plate retractor (already purchased from AutoLoc).  Install LED taillights (already purchased from Hagan Street Rods, and mounted in the body).  Install all-new convenience module from Painless Performance Products (see sidebar “Install a Painless Convenience Module” below). Install a Painless Convenience Module In this day and age, there is really no reason to be stuck with 1970s functionality in your hot rod or classic. The Painless module that I used in the install has been discontinued. Dakota Digital offers a similar module. Both include a host of modern vehicle features and can be installed in any vehicle, no matter its age. Here are the features offered by the Dakota Digital PAC-1300:  Dome light delay and dimming. When you’re entering the vehicle or after you’ve turned off the key, this feature keeps the dome light on for a user programmable length of time. After the delay period, the dome light gradually dims to off.  Headlight delay. This feature leaves the headlights on for a user programmable length of time after the ignition switch has been turned off, assuming, of course, that they were on before the ignition was turned off.  Retained accessory power (commonly referred to as RAP on late-model vehicles). This feature keeps the accessories powered up for as long as 20 minutes after the ignition switch has been turned off. If you open a door before this time is up, the delay period automatically ends. This allows you to use the radio, power windows, and other accessories. This feature is handy for those times when you need to drop someone off for a quick errand while you wait in the car.  Automatic headlights. This feature turns the headlights on automatically when it gets dark and turns them off automatically when it gets light. This is done via an included dash-mounted light sensor.  Voltage monitoring system. This feature shuts down the vehicle’s lights and accessories below a certain voltage threshold. This prevents draining the battery so that the engine can be started.

This Dakota Digital PAC-1300 module is inexpensive and easy to install. Okay, now that’s a bunch of stuff. But it gets better. He then told me about the seats that he wanted to use in the Willys: a pair of fully electronic/pneumatic power seats from a wrecked Mercedes. (I knew that the seats and interior lighting switching would present two of the biggest challenges.) We discussed the possibility of using the door contactors to activate the interior lighting, and he liked that idea. Finally, I recommended using a three-wire internally regulated alternator, as I’m a big fan of them. Outline the Considerations I saw Mike again about two weeks later to see the seats and some of the billet switches in person. I’d done a lot of research and had some answers for him. I recommended a Painless 18-circuit remote wiring harness supplemented by rear- and front-mounted auxiliary ATC fuse panels. In addition, I would need a relay center in the rear and in the front to accommodate all of the high-current accessories. Last, I recommended using the keyless entry system to also open and close the windows, turn the headlights on and off, and turn the audio system on and off. We agreed. Then, he showed me the Mercedes seats. When I looked under the seats at the OEM electronics, I realized that they would require serious modifications for use in this project. The next day, I was gathering information about the seats from Mitchell 1, a reference website for factory wiring data. The seats were actually from a 2004 CLK55 AMG, a vehicle that Mitchell 1 considers “low production.” But, Mitchell 1 was able to furnish me with a diagram of similar seats from another vehicle that closely matched these (Figure 6.1). The door-mounted switches connect to a doormounted control module via the CANbus. Furthermore, the CANbus connects this module to the motor control modules mounted under each seat. My first thought was that I would need those control modules from the salvaged vehicle. It was time to step back from this a bit and come up with a different plan. In the meantime, I contacted my uncle Jimmy for his advice on a simple circuit for the interior lighting. He e-mailed me a schematic right away using parts that I could obtain locally from RadioShack. Problem solved.

This is about two-thirds of the goodies going into this vehicle. Get everything out of the boxes so that you can establish some initial component locations within the vehicle. Once that is done, repack each piece, as well as any included mounting hardware and instructions, in its original box until you are actually ready to install that particular component. Otherwise, you quickly run out of working space, and you lose or misplace critical components.

Figure 6.1.

List the Parts Required Based on our two meetings, I ordered the following parts to complete this project:  Painless 18-circuit remote-mount harness kit, PN 10220  XS Power S3400 AGM battery  Taylor aluminum battery enclosure, PN 48100  JL Audio 1/0-, 4-, and 8-AWG power and ground wire  Painless PowerBraid chassis kit, PN 70920  Painless Weather Pack connector assortment, PNs 70402, 70403, 70404  Some additional Painless PowerBraid, PNs 70901, 70902, 70910  Painless PowerBraid tool kit, PN 70941  Painless convenience module, PN 63040  Painless single fan controller, PN 30141  MSD 6-BTM ignition, PN 6462  MSD HVC II coil for a 6 Series ignition, PN 8253  MSD firewall feed-through, PN 8211  Six- and nine-position ATC fuse holders (available at www.ceautoelectricsupply.com)  AutoLoc ten-channel keyless entry system, PN KL1000  (2) Rockford Fosgate 200-amp circuit breakers to protect the run of wiring from the battery to the front of the car, PN CB-200  (2) Rockford Fosgate RFD1 distribution blocks  (1) JL Audio XB-MFBU-ANL fuse holder  Numerous SPDT relays  Parts required from RadioShack to build the interior light activation circuit The convenience module and fan controller from Painless were not available to me at the time I took delivery of the vehicle, nor would they be until after I had completed the initial installation; neither was in production yet. In lieu of having the actual product, I obtained the wiring diagrams for both from Painless, and Painless happily answered my installation questions. Therefore, I was able to plan accordingly so that I could easily add these when they became available. When I took delivery of the vehicle, I still had not come up with a solution for the Mercedes seats. Because this was the one variable yet remaining, I had to tackle it right away so that I could get to the next step in the process and begin the actual work. After looking at the seats on my bench with a fresh mind, I realized that the electronic controllers were simply connected to five 12-volt DC motors. I used the battery from my cordless impact driver to power each motor in both directions to verify this. Given that it’s easy to make a DC motor move in two directions, I had this problem solved. My solution was to remove the OEM motor controllers entirely and design my own interface from scratch. This did require some other kind of power seat switches, as the stock Mercedes switches could not be used. Why? Because their outputs were designed to interface with the CANbus, and they used proprietary connectors. After 20 minutes on eBay, I determined that some power seat switches from a mid-1980s BMW 5series car had the exact same legend of directional movements printed on them as on the Mercedes seats. In addition, they had traditional ins and outs for all five switches. I purchased a pair for the lowly sum of $37 including shipping. At this point, I was pretty confident I had everything I needed to begin the actual work. Create a Diagram

I always recommend creating a diagram. However, a complete diagram for a project of this scale really isn’t feasible. That being said, I recommend drawing a block diagram like the one shown in Figure 6.2 to keep things straight. Then, make a list of the required relays, what accessories they power, and how they are triggered. All accessories that you desire to work only under certain conditions, such as when the ignition switch is in the ACCY or IGN/RUN position, require a relay. Relays are also required for accessories that you desire to activate remotely from a keyless entry or security system. This process helps you determine how many auxiliary fuse panels you will require, how much current they should be capable of supporting, and the various sources of power you need to make available to the relay center.

Figure 6.2. A diagram like this one is helpful to plan a big project like this. It may also be necessary to draw complete diagrams of various parts of the project, such as the power window interface, for example. As I work, I typically keep notes on a yellow pad so that I don’t forget certain things. Choose Suitable Mounting Locations At this stage, you should get all of the components out of the boxes and choose suitable mounting locations for them. When installing numerous accessories, it is best to locate them in common areas to simplify your work. Also, do your best to choose a location that allows you enough room to locate the auxiliary fuse panel(s) and relay center near the components. By doing this, you greatly simplify troubleshooting your work should it be required. For the Willys, I decided to use the rear dividing wall as the primary component location and the aluminum plate behind the instrument cluster as the secondary component location. The primary location included these components:

       

Main fuse panel Rear secondary fuse panel Rear relay center Keyless entry system Motor controller for the license plate retractor Circuit breakers Fuse holder for the power feed to the front fuse panel Rear ground distribution

The secondary location included these components:   

Front secondary fuse panel Front relay center Ignition box and coil

Because this is a fiberglass vehicle, I located ground distribution centers in the trunk, on the rear dividing wall, and behind the instrument cluster. Finally, as I always do, I used the frame as the return path for everything: the charging system, all accessories, everything. The frame has lower resistance than any piece of wire you’re likely to use in an automobile. Therefore, it makes an ideal return path for even the highest-current accessories, such as the starter, for example. I don’t care how careful you are in the planning stages; I guarantee that something will throw you for a loop during a project like this, and you will have to be able to adapt. So, do your best not to paint yourself into a corner. As you will see, I ran into a few challenges at various points in this project. I chose to illustrate them and show you the workaround rather than use the magic of editing! So, let’s get to work. Part 1: Begin the Project As you unpack the wiring harness, you will notice that Painless includes several bags of loose subharnesses for the headlight section, tail section, engine section, accessory section, etc. It simply isn’t possible for a company to pre-assemble these things in universal harness kits. Rather, the installer adds these sub-harnesses as the main harness sections are cut to length. Prepare wiring harness. Remove the ties from the main wiring harness and carefully separate the sub-harnesses so that you are able to mount the fuse panel. Take your time here, especially with a rear-mounted universal harness, as it is extremely long. Several sections of wire are tied together. For clarity, I refer to these as subharnesses and the bagged harnesses as loose sub-harnesses. I’ve used Painless products frequently. I’m always impressed by the quality, and this kit is no exception. Every single wire is clearly labeled over its entire length, and Painless uses extremely highquality thermal cross-linked (TXL) polyethylene wire rated at 125 degrees C (275 degrees F) for all of its harnesses. In addition, each section of the harness is long enough so that there is no worry about having to extend it. Also, the gauge of wire chosen for each circuit is certainly up to the current-carrying task given the typical length you need. Finally, I like the fact that Painless provides a maxi fuse holder and 70-amp maxi fuse to protect the wiring harness from damage. This is far superior to a fusible link.

The 18-circuit universal harness kit from Painless includes the fuse box/harness assembly, a number of sub-harnesses, all of the hardware that you need to install the kit, and two GM-style plugs for the ignition switch, turn-signal switch, three-wire internally regulated GM-style alternator, and headlights. It also includes an assortment of crimp-type connectors, grommets, wire ties, and a Painless Maxi fuse holder, complete with a 70-amp maxi fuse. This is the main fuse for the fuse panel, and it is used in lieu of fusible links. Smart. Mount fuse panel for wiring harness. Early on in this project, I determined that I would be mounting the fuse panel on the rear dividing wall. I decided on the interior side of this dividing wall for ease of access, both during the installation and for serviceability afterward. I used the provided metal bracket as a template for drilling the holes in the dividing wall. I mounted the panel directly over the wheel tub.

I chose this location for a few reasons. It allows me the ease of performing most of the work from a comfortable position in the interior of the vehicle. To the right, I left room for the Painless convenience module, and to the left, I had room for all of the other components that would be installed in the rear.

Route harnesses. This is a critical step in this process; here is a method that allows you some flexibility if you make a mistake at any point during installation. I typically do not use wire ties in such an installation, as they are semi-permanent. Rather, I prefer to group sub-harnesses together that are routed in a common direction and secure them with 3M Scotch Super 33+ tape. This allows far more flexibility than wire ties, and I hate having to cut them off to replace them. Tape is inexpensive and easy to remove. From this point, a sub-harness can only go in one of five directions: 1. 2. 3. 4. 5.

To the tail section To the front of the vehicle To the center console To some point on the rear dividing wall to the left of the fuse panel To some point on the rear dividing wall to the right of the fuse panel

Your application may be different, but the process is the same. Take your time and look through every sub-harness and every individual wire in the wiring harness and separate them according to the direction they are routed. As these wires are very long, this takes a helper to divide them up without tangling them. Once they are separated and grouped together based on direction of routing, tape each of the sections with one piece of 3M Scotch Super 33+ tape close to the fuse panel.

I drilled a 1-inch hole in the rear dividing wall to allow the tail section of the harness to pass through in such a way that I could keep it alongside the body to the rear of the vehicle. Even though this rear dividing wall is made of wood with a layer of fiberglass on the rear, I still installed a snap bushing to protect the wiring as it passes through the barrier; this is always good insurance. It is now time to install the first loose sub-harness. This is the one that travels from the tail section to the dash area of the vehicle, and it includes the wiring for the turn signal/brake lights, the fuel level sender, and the taillights.

Run the first loose sub-harness from the kit to the tail section. Wire convenience module. If you are not installing this component, skip to the next step. For now, I connected the ignition, turn signal power, switched feed to the radio, and parking lights to the main harness according to the diagram supplied by Painless. I soldered these connections. The dome lamp (–) and headlight dimmer switch input connections to the harness will be made at a later date, but they need to be routed in the correct direction.

This is what your garage floor is going to look like at this point in the process. Keep tools and extension cords clear of this area. As I mentioned, I didn’t have the actual kit at the time of writing, but it should be available to you by now. It is best to install such a device that has numerous connections to the wiring harness early in the project while the wiring in the harness is easily accessible. For now, the best I can do is terminate those

connections at a barrier strip so that, when I do get the kit, connecting it will be a snap. Barrier strips are readily available in four, six, and eight positions at your local RadioShack.

Because I didn’t have the Painless convenience module at the time of installation, I pre-wired for it so that I could easily install it when it became available. I obtained the wiring diagram from Painless, which provided all of the information that I needed. I used a simple six-position barrier strip for this. On the barrier strip, from top to bottom, are ignition, turn signal power, parking lights, headlight dimmer input, switched feed to radio, and dome lamp trigger (–). Note the sub-harness with green, blue, and violet 16-AWG wires. The green and blue wires are for the license plate retractor motor, and the violet wire is for the trunk release solenoid.

The tail harness is taking shape. Included in this run are the wiring for the turn signal/brake lights, fuel level sender, taillights, power antenna trigger lead, power lead for a trunk light/power antenna, back-up lamps, and trunk opener solenoid. Also included are the wiring from the motor control module to the license plate retractor motor and the main ground for the tail section. I ran a 12-AWG wire for this. No, I didn’t forget that there would be no back-up lamps installed in this vehicle, but I ran the wire to the rear and terminated it there just in case Mike changes his mind later.

Per the instructions for the convenience module, I stripped the orange and brown wires to the ignition switch so that I could connect wiring to them.

Solder the connections.

Insulate the connections with 3M Scotch Super 33+ tape. Mount harness. This is one of the tricks I mentioned earlier. Use plenty of rubber-lined metal cable clamps to provide a solid mounting for the harness as it travels to the front of the vehicle. This allows you to easily add wiring from the rear to the front of the vehicle should you forget something or decide to add a circuit later. Forget something? No problem; just slide it through the loops.

Use rubber-lined metal cable clamps to neatly group together all of the sub-harnesses and loose wires that travel to the front of the vehicle. I used the largest one I had on hand, 1 inch (a no. 16 clamp; the 16 refers to the number of 1/16s). I mounted these clamps to the 1/4-20 bolts that hold the fender to the body. Install doorjamb pin and contactor plates. Mike purchased these components from Keep It Clean Wiring, and they are available in numerous configurations. He chose the six-pin variety, which covers the door poppers and power window motors, and it leaves two pins for me to use for activating the dome light, detailed later in this chapter. Use the following steps to install these parts.

This pair of doorjamb contactors was purchased from Keep It Clean Wiring. The pins are springloaded; they can be pushed completely into the body when the doors are closed.

Making connections to these can be a bit of a challenge. Although a traditional 1/4-inch push-on connector fits on the connector at the right, it makes it very difficult to get it back into the mounting hole. The brass pins on the one on the left connector are even more difficult, as a traditional bullet connector doesn’t get a very good bite on them, and they are constantly moving back and forth with the door opening and closing. The solution? Solder.

Strip about 3/4 inch of insulation from the wiring, and wrap it tightly around the brass contact. I used my trusty RadioShack two-hands tool here to support the connector.

I found it easier to clamp the pinned connector to the bench to solder these connections. You need a solder gun. Also, some kind of heat sink is required to prevent the surrounding plastic housing from melting during the soldering process. I used a small pair of locking pliers for this. It directs excess heat from the pin into them, thereby preventing the housing from melting.

Shown here is the completed connector. Colors and functions, from left to right, are: white, dome lamp activation loop; light green and tan, power window motor; green and blue, door pop solenoid. I used heat-shrink tubing to insulate these connections. Be sure to only heat the heat-shrink tubing with the pin fully out of the housing; as in, not clamped to the workbench. This way, the pin still has full travel.

Clamp the contactor plate to the workbench, and lay the pinned connector in front of it so that you can get the correct pins lined up with the correct contacts.

Tin each wire in preparation for soldering them to the connectors on the contact plate.

After each of the wires is soldered to its corresponding connector, insulate each one with heat-shrink tubing. These wires were quite long in this application; the two white wires have to run all the way to the rear dividing wall to the left of the fuse panel, and the wires to the door lock solenoid and power window motor have to run to the front relay center. Plan accordingly.

I used quick disconnects between the pinned connector and the door lock solenoid and power window motor. In this case, I used 1/4-inch fully insulated push-on connectors. This makes the job of replacing a failed component easy. I always fill the bodies of such connectors with white lithium grease when they are subjected to the elements. And, yes, the bottom of a door is one such area.

Shown is the installed pinned connector. These are pretty slick.

Drill a hole in the body for a snap bushing.

Install a 3/8-inch snap bushing in the body to allow the cables to pass through from the contactor plate.

I left a 6-inch harness from the body to the contactor plate. This allows the painter to remove the contactor plate, tape it out of the way, and paint the sill without having to disconnect it. I covered this length with Painless PowerBraid and used heat-shrink tubing to terminate the ends of it neatly to the harness.

Install the contactor plate, and route the harness through the floor into the vehicle. Mount main fuse holder for fuse panel. Obviously, this differs for a rear-mount installation and a front-mount installation. In a traditional harness installation, you typically tie the main power to the battery positive (+) post directly. You may also tie it to the terminal on the starter that is supplied by the battery positive (+) post. Either way, be sure to mount the fuse holder within 24 inches of its power source. Also, be sure to mount the fuse holder vertically with the cover on top so that it does not collect water.

Select a safe location for the main fuse holder; it must be within 24 inches of its source of power. Cut the main power wire, crimp the supplied ring terminals to each half of the power wire, and connect each to the fuse holder.

Mount other main components. It is time to begin mounting the other main components. I have a bunch of real estate on this rear dividing wall. I’m doing my best to leave enough room should I have something come up unexpectedly during the installation.

At this point, begin mounting the other main components. Shown from left to right are the keyless entry, the motor controller, a JL Audio fuse holder, a few relays, and a six-position ATC fuse panel that will be used to provide power to the relays and other high-current accessories. Begin wiring components in rear. This would be when it makes the most sense to begin wiring the components on the rear dividing wall. Some of them require runs to the front of the vehicle, others to the console area, and even others to the rear of the vehicle. However they’re done, you need to get that sorted out before you go any further. A. Begin wiring the relays. I’m using relay sockets for this vehicle. Because they are not readily available with 10-AWG wiring (and I need some that way), I’m making my own. Pre-wired relay sockets such as these are readily available with up to 14-AWG wiring from www.ceautoelectricsupply.com. Keep in mind that you also have to purchase the connectors, which are also readily available for 12-10-AWG wiring and 16-14-AWG wiring. The connectors for the 22-18AWG wiring are pretty elusive, for some reason. B. Wire the power and ground distribution for low-current accessories. Because this vehicle has a fiberglass body, I need an easily accessible place on the rear dividing wall to connect numerous lowcurrent grounds, such as those for the keyless entry, motor controller, and several of the relays. This is another great place to use a barrier strip. I chose an eight-position strip for this application, as I also needed a place for low-current connections to the ignition and accessory circuits of the ignition switch. This accommodates all three.

For this vehicle, I used relay sockets for each of the relays installed in the front and rear relay centers. This is more time consuming than using fully insulated 1/4-inch push-on connectors, but it allows a relay to be quickly and easily unplugged should one fail. These are slightly different units. On the right are my old favorites, the Tyco 30/20-amp relays (formerly offered by Bosch). These are available at places such as Parts Express. The relays on the left were included with the power window harnesses from Keep It Clean Wiring. I used them for some lower-current duty, as Mike already had them.

The easiest way to wire the relay sockets is to terminate the wires themselves, and then slide them on the correct terminals. When all of the terminations have been made, remove all the connectors, and insert them into the relay socket. Push them in far enough so that you hear a click as the retainer pin locks into place. The correct tool for this job is a U-barrel crimp tool. I use an Ideal die (PN 30-586) that fits in my Paladin crimper.

This is what the barrier strip should look like when it’s completed. Notice that the fork terminals in the first, fifth, and seventh positions are upside down. This arrangement allows me to stack the feeds for the ground, ignition, and accessory circuits on top of those while leaving the other side of the barrier strip totally open for use. Feel free to double-stack fork terminals under each screw when using barrier strips, but don’t exceed 20 amps on any of the individual circuits. After mounting the barrier strip to the rear dividing wall, mount the fuse holder to protect the power feed to the front ATC fuse panel; this is a clever fuse holder that I bought from JL Audio (PN XBMFBU-ANL, available at any of its dealers). In addition, I mounted the wiring harnesses for the keyless entry and motor controllers. I advise you to think about serviceability here; plug the harnesses into the respective units, bundle the harnesses appropriately with 3M Scotch Super 33+ tape, and mount them so that you have enough slack to easily unplug them should the need arise. Once mounted, unplug the harnesses from the modules. For now, just pull the harnesses out of the way of your other work.

The barrier strip is mounted. I also mounted the fuse holder that will protect the power lead that will feed the frontmounted ATC fuse panel and the wiring harnesses for the keyless entry and motor controller.

The barrier strip is installed, wired, and ready to be put to work. I connected the 12-AWG ground wire (ground for the tail section) to the fourth position up on the barrier strip by stacking it atop the other fork. The ignition circuit is tied to the fifth position up, and the accessory circuit is tied to the seventh position; it’s just as I planned. C. Install the main ground distribution block. At this point, it should be pretty obvious that many things are dependent upon one another. The barrier strip I just installed doesn’t do me much good on the ground side of things if I don’t supply it with an excellent ground. I really like the distribution blocks from Rockford Fosgate, and I have used them frequently over the years for projects like this. I like them because they are typically quite compact and offer lots of flexibility. The one used here (PN RFD1) has a single input and dual outputs. Either can accept up to 1/0-AWG wire and include 4-AWG reducers. For now, I’m just going to be adding a single 8-AWG wire to supply the barrier strip.

Mount the main ground distribution block, and connect an 8-AWG wire from one of its outputs (top) to the barrier strip at the right. This 8-AWG wire connects easily to the first position of the barrier strip, stacking it atop one of the jumpers. This requires an 8-AWG no. 8 fork terminal.

D. Wire the electric fuel pump. As I noted earlier, Mike may be upgrading the installed fuel pump to a substantially larger unit. He requested that I plan for that. You may not require such a large fuel pump in your application, so I’m illustrating how to connect the existing one. The 18-circuit Painless harnesses include a power lead suitable for powering a small electric fuel pump. If you use that, I recommend that you wire a 15-amp SPST switch in line on that wire so that you can turn the fuel pump off if you choose to do so. In this installation, I wired the fuel pump via a 30-amp relay and used 10-AWG wire for the power feed. This allows Mike to install a fuel pump with up to 30 amps of current requirement. (Instead of letting it go unused, I ran the fuel pump power lead from the harness to the console area to power the fuel pump switch, which, in turn, activates the fuel pump relay.)

This fuel pump was already mounted to the frame rail. Given that it requires less than 10 amps of current, and the frame is powder-coated, I connected its ground wire to one of its mounting bolts. This is a stainless steel 10-24 bolt threaded into the frame. I removed the bolt and used a small wire brush on the end of my rotary tool to be sure the threaded hole was free of paint. I then put star washers between the frame and bracket and between the bracket and bolt to ensure a good electrical bite. Finally, I used white lithium grease on the threads of the bolt as I installed it.

I drilled a hole in the floor of the trunk as close to the frame rail as possible. I passed the 10-AWG power lead down through a 3/8-inch snap bushing and covered the lead with some PowerBraid.

Connect the 10-AWG feed to the power lead of the pump via male and female fully insulated connectors. Yep, fill the female with white lithium grease before plugging them together. This will provide a troublefree connection for years. E. Continue wiring the relays. The relays from right to left in the photo below are for the trunk pop, fuel pump, audio system on/off from the keyless entry, and the parking light output from the keyless entry. I always recommend using a diode across the coil in reverse bias. I overlooked the diode on the trunk opener relay. Don’t worry; I caught it, too, and will address it shortly.

Shown is the completed socket with all of the terminals snapped in. Build interface for power seats. Now, you may not be installing power seats out of an exotic car in your hot rod, but after you read this section, I can assure you that you’ll think, “That’s cool!” As I discussed earlier, what we are really dealing with here is five different DC motors. Refer to Figure 6.1. No matter how complex it looks, rest assured that the OEM controllers mounted under these seats have a similar interface to what I’ve designed. (The other connections to the motors are for positioning information for the memory circuits; I won’t be using them.)

Here are the seats. They were removed from a wrecked 2004 Mercedes-Benz CLK55 AMG. At the end of the day, all DC motors turn one way when voltage is applied to one terminal and ground is connected to the other. Reverse this, and the motor’s direction also reverses. This is commonly referred to as voltage reversal, and it is the same principle that governs the operation of power door locks, power windows, power sunroofs; any accessory with a DC motor. The circuit to do this is simple, and it can be done via relays or solid-state devices, such as MOSFETs (metal–oxide–semiconductor field-effect transistors). To keep things simple, I’m using relays for this project. Figure 6.3 illustrates this very simple circuit using relays. So, how many do I need? 5 motors × 2 relays each = 10 relays. No worries; I have all kinds of room under these seats. In the overall scheme of things, relays are also fairly inexpensive and readily available.

Figure 6.3. This diagram illustrates two relays negatively triggered to operate any DC motor in both directions. If you look closely, you will notice that both motor wires rest at ground via terminal 87a. When the FORWARD/UP switch is depressed, the relay on the right connects 12 volts to the right motor wire, which causes the motor to move in one direction. When the REVERSE/DOWN switch is depressed, the relay on the left connects 12 volts to the left motor wire, which causes the motor to move in the opposite direction.

I simply removed the OEM motor controller. Referring to Figure 6.1, I was able to quickly determine the actual motor wires and cut them from the OEM plugs. As the motors have “12 VDC” printed right on them, you can connect a battery from a cordless drill to each of the motors to verify operation. Reverse the wires, and the motor reverses.

Now, before you construct an interface like this, you have a couple decisions to make. The first pertains to the type of controller you want to use and how it works electrically. In this case, I had already decided on the BMW 5-series controllers. When I bought them on eBay, it looked as if they were made of five SPDT switches that rested open. Once I had them in my possession, I was able to verify this, so I was able to wire them any way that I chose. Your second decision pertains to when, exactly, you want the seats to operate. I discussed this with Mike, and we both agreed that it would be best if they worked regardless of the position of the ignition switch. After all, this is the way that most power seats are wired from the factory. But, let’s say that, for whatever reason, you want the seats to work only when the ignition switch is in the ACCY or RUN position. No problem; refer to Figure 6.4.

Figure 6.4.

These BMW 5-series power-seat switches are perfect for this application, especially because they can control the headrest up/down motions of the Mercedes seats. On the rear, each of the five switches has three poles: one common, and two normally open. Each button is spring-loaded, so when you release it, the switch rests open; there’s no connection between the common and either normally open. The bottom switches are vertical according to the screen-printed legend.

I used an 18-inch metal strap to provide a solid mounting surface for the 10 relays. I mounted this to the top of the seat tracks using the same hardware that held the OEM mounting bracket. I grouped the relays in pairs, two per motor. Here is a chart that illustrates exactly how I kept things organized:

Here are the first electrical connections to be made. Each of the motor wires needs to be connected to terminal 30 of one of the two relays for that motor. I connected the white wire to the upper relay, and I connected the other motor wire to the lower unit in each pair to keep things straight.

Per Figure 6.3, the wiring to the relays has been completed. This is really quite simple: First, I used three separate runs of 16-AWG wire for power and ground (red and black, respectively) to supply the relays with power. One run feeds the top four relays, another run feeds the next four relays, and the third run goes to the lower two relays (these relays feed the largest motor shown just to the right of the relays). Second, the wiring separates into two harnesses at the bottom: one for power and ground and one to run to the BMW seat controllers.

To make these seats truly plug and play (as the factory would), I used these 12-circuit Molex connectors (PN 1360PRT). This kit is inexpensive and includes male and female plug bodies, as well as male and female pins.

I soldered 1/4-inch male push-on connectors onto the ends of the 16- AWG wires and finished them with heat-shrink tubing. These are designed to snap into a plastic housing, such as those used on aftermarket electric fans, available at www.ceautoelectricsupply.com.

Here, the connectors are shown snapped into the plastic bodies. The bodies are female.

Take your time when crimping these pins on the wires. It is very tedious. I always pull-test each connector to be sure it is both electrically and mechanically sound. The assembled plug (bottom left) is the harness from the seat, and it has a female plug body with male pins. The harness without the body (right) is one end of the extension harness from the seat to the switch. This end has female pins, which will be snapped into the unattached male body.

I wired the BMW switches in accordance with the chart on page 163 per the legend on the front of them. I used crimp-type push-on connectors only for the ground connections (the common pole of each switch) and soldered the rest. Be sure to use a heat sink to keep heat from damaging the switch assembly. There are two identical switches.

I wrapped the power/ground plug and the seat switch plug individually with PowerBraid. This protects the wiring from the sharp edges of the metal strap and the OEM metal bracket that spans the width of the seat. I taped the PowerBraid to the harnesses with 3M Scotch Super 33+ tape to provide a clean finish.

Each switch was terminated with female pins in a male plug body. Obviously, this plug has one more wire in it than the seat plug: the ground input for each of the switches.

I made this extension harness. It extends from the seat bottom to the console-located switch, and there is one harness for each seat. One end has a female plug body with male pins, and the other end has a male plug body with female pins. The ground wire on the left provides ground to the switch. Now, I told you this was one slick interface. These control the pneumatic functions of the seats. Specifically, they are used to inflate and deflate the various cushions in the seats. Mercedes refers to these seats as MultiContour seats. I obtained the OEM pump from the same place Mike purchased the seats. Some seats also include ventilation; these do not. Another factory option was to have heating elements in the seat bottom and seat back, and these seats do include them. According to the diagram supplied by Mitchell 1 (Figure 6.5), the circuit is pretty simple. A little investigation revealed that the OEM controllers use pulse width modulation (PWM) to control different levels of heating. I'm not going to get that fancy here. I connected the seat heaters directly to a 12-volt power supply and monitored the seat cushion temperatures with an infrared thermometer. They

worked like a charm. In the car, I used console-mounted switches to activate relays on the rear dividing wall to power the heaters.

I wrapped each extension harness with PowerBraid. The ground wires will later connect to the main harness in the center console. Shown in the center of the extension harness is a short length of the OEM harness for the seat heaters.

The gray tube is the input to the MultiContour switch panel. This panel, located on the inner side of the seat bottom, controls the inflation and deflation of the various cushions in the seat.

Figure 6.5. Part 2: Time to Adapt Earlier, I warned you that there would be a time in any project like this when you may have to change your plans slightly. It’s best to assume this will happen and do your best to be flexible when it does. In this case, I was unsure of whether or not I would be using the seat heaters; after all, do you really need them in Phoenix? Regardless, Mike was so excited with the progress I had made with everything else that he decided that he’d like to have this feature, too. This necessitated a pair of additional relays that I simply didn’t plan for and a larger ATC fuse panel on the rear dividing wall.

I was easily able to fit a nine-position ATC fuse panel in place of the six- position unit; I just had to orient it horizontally instead of vertically. This panel provides enough fuse locations to address the seat heater relays. I added another relay on the left. This is to turn the headlights on or off via the keyless entry system. I also used some temporary labels to keep things straight as I wired. Finally, notice that the fuel pump relay (second from right) has a metal tab. This is a 40/30-amp Tyco relay; it has 40-amp surge and 30-amp continuous.

Pictured are the harnesses for the keyless entry system. Although I am only using seven of the ten channels, I am leaving some length on the rest of the harness. This will come in handy should Mike ever want to add something else. The harness in the middle will be routed to the front and will control the door locks and power windows from the keyless. I extended these wires accordingly.

I need to fit two more relays for the seat heaters. As you can see, I moved the motor controller over about an inch to the left to make room for one of the relays. Because I hadn’t hooked up any of its harness yet, I was free to move the controller. The cable clamps easily allowed for this. I also added a diode across the coil in the relay (on the far right).

To make room for the other relay, I simply moved the maxi fuse holder to the right slightly. In addition, the motor controller was wired. The second relay from the left controls it. I wired it per Figure 6.6. The following chart duplicates the legend on the relays mounted on the dividing wall (no. 1 is to the far left):

The following chart duplicates the legend on the rear ATC fuse panel (no. 1 is to the far left):

You will also notice an in-line fuse holder just above the barrier strip. This is to protect the accessory wiring run to the console area.

Figure 6.6. This is the diagram for all of the rear-mounted relays. The fuel pump and seat heater relays require a positive (+) trigger from the switch to activate them. The reason for this is that those switches will likely be illuminated. Illuminated switches typically require that they are wired to switch positive in order to illuminate when in the on position. Wire ground distribution for high-current accessories.

Both seat heaters, the relays for the power seat functions (under each seat), and the air pump for the seats require large-gauge ground connections. In addition, I ran a 10-AWG ground wire into the trunk alongside the 10-AWG power wire for the fuel pump. That way, if Mike installs the larger fuel pump in the trunk instead of on the frame, he’s covered.

All the jumpers are installed and this is now ready to go in the vehicle.

I installed the high-current jumper to the right side of the main ground distribution block. I ran a short length of 8-AWG wire from the lower bolt on the barrier strip to the main ground distribution block. This is an excellent time to check that all of the screws on both barrier strips are very tight. I’ll remount the JL Audio fuse holder later.

I ran the ground wires from the large barrier strip along the bottom of the rear dividing wall, and I grouped them with the respective power wires for each seat heater and each relay cluster under the seats. I ensured that these were long enough to reach the seats without having to extend them later. Route harnesses to center console and seats. Group together all of the wiring going to the center console and seats; begin to get that in order. I’m being as neat as I can here, and I am considering that, at some point, an interior will be built in this vehicle. Therefore, I am cautious to keep as much wiring as close to the vehicle’s body as possible.

The harness between the rear dividing wall and console and seats is beginning to take shape. For now, I decided to hold it together with a few cable ties. Also shown in this picture is the white/black wiring at the right. This is the wiring from each of the doorjamb contactor plates and the convenience module for the dome light. Finally, the 18-AWG blue wire is the remote amplifier turn-on lead, and the 16-AWG black wire is a ground lead for low-current switching in the console.

I soldered the 12-AWG feed from the seat heater relay and ground wires to the OEM pigtail. I also terminated the 10-AWG power/ground wires for the relay clusters under the seat with the matching male connector to the one that I installed earlier.

I’ve routed the harnesses as a single group along the body lines. Hopefully, this will make the interior guy’s job easy.

I covered this harness with PowerBraid to protect it from the moving seat. A. Terminate the center console harness with a 15-pin Molex plug. A bunch of switches go in this center console. At this time, where they will go, exactly, has yet to be determined. So, I’m going to make this easy. I’ve terminated the rear console harness with a 15-pin Molex plug (male body, female pins). A front console harness of the same size will also be built in Step 4 of Part 4.

The console harness from the rear dividing wall has been terminated with a 15-pin Molex plug. It contains all of the wiring for about half of the console-mounted switches, as well as a few power connections and a ground. I also installed the extensions from the console-mounted seat switches to the seats.

The console harness, power harness, and seat switch extension harnesses are all tied neatly together. I put the seats in the vehicle for this step so that I could get the length spot-on. When the console is built, and Mike has all of the switches he intends to use, I can wire them all and install the mating plug. This kind of planning makes it easy to remove the center console should it ever need to come out; it likely will need to come out in this vehicle, as the console sits atop the access panel for the transmission. Could you imagine how difficult this would be with the number of switches in it if I didn’t install Molex plugs? Think serviceability. B. Install the extension harnesses to the seats. They’re already built. All you need to do is install them. Wire tail section of vehicle. In a project of this scale, tackling each sub-project is like a breath of fresh air. In this case, I’m moving to the rear of the vehicle so that I can wire the tail section. A. Install a barrier strip. You need to install a barrier strip in the trunk that allows you to easily distribute ground for all of the rear lighting, power antenna, fuel level sending unit, fuel cell, and trunk lighting. Also, it provides a point of commonality for the power side of the trunk lighting.

Install a barrier strip that can be used to distribute ground in the tail area of the vehicle. I connected the 12-AWG wire I previously ran for this purpose to the barrier strip. This barrier strip is used as a place of commonality for the trunk lighting, so I used a six-position strip. Mike prefers this to be on the back of this mounting surface (a support between the trunk floor and quarter just behind the wheel tub on the driver’s side), so I’ll wire accordingly so that I can easily move it later.

Connect the grounds to the barrier strip for the lower-left light assembly, upper-left light assembly, lower-right light assembly, upper-right light assembly, back-up light, trunk light switch, power antenna, fuel level sending unit, and fuel cell ground. Tape the ground wires along the corresponding wires for ease of wiring the individual components. B. Connect the LED lights. Mike installed LED lighting in the body; he bought the lighting from Hagan Street Rods. There is an upper and lower kit on each side. Each has a strip of LEDs mounted within it and includes a current limiting/isolation/voltage-divider network. It is imperative to install these networks for correct operation and to avoid damaging the LEDs. Fortunately, it’s a piece of cake!

Install the included networks for the LED lighting on each light. Because this vehicle has two per side, there are a total of four networks.

Per the instructions, I connected the taillight wiring from the Painless harness to the black wire on one network and to the brown wire on the other. The turn signal/brake light wiring was connected to the yellow wire on one network and to the green wire on the other. This way, both the upper and lower LED lights perform brake/turn/taillight functions. The black wire on each of the LED lights is grounded. C. Connect the trunk lighting switches and harnesses. Although the trunk lighting won’t be installed during this project, there are two switches to install to control it; one is activated by raising the trunk lid, and the other one is activated by a master on/off switch. In addition, I can install the harnesses to the lights.

Tie the harnesses together neatly. Special Considerations with LED Lighting Generally speaking, a flasher is a pretty archaic device. The flasher is wired in series on the power input lead of the turn signal switch. That way, a single flasher can work both left and right turn signals. (Another flasher is typically required for the hazard lights.) A flasher requires a load of at least a few amps through it in order to work properly, which is no problem for standard incandescent light bulbs.

LEDs require substantially less current; think milliamps (see Project 2 in Chapter 1). This is one of the reasons that they have become so popular. When you upgrade your turn signal bulbs to LED lights, they do not flash via the standard flasher because they simply do not draw enough current through it. Fortunately, this is not a problem. Simply remove the OEM turn signal flasher, and replace it with a no-load flasher. Problem solved. A benefit of this kind of flasher is that the flashing speed is fixed. As a regular flasher heats up (such as at a long red traffic light), its flash rate typically speeds up, due to the heat trapped within it.

This example of a no-load flasher is by Keep It Clean.

Connect a pair of 18-AWG white wires and 18-AWG orange wires to feed the trunk lights. I routed these harnesses just behind the wheel tub on each side and terminated them with female bullets. The green wire is from the Painless harness, and it is the power feed for the trunk light and power antenna.

The green and orange wires are for the master on/off switch. The green wire is power in from the Painless harness, and the orange wire is power out to the lights. This switch affects the power side of the lighting harnesses.

These are the harnesses on the passenger’s side for the trunk lighting and the power antenna. The purple/black wire is the trigger lead, the green wire is the power, and the black wire is the ground.

The tail section is now complete, with the exception of the switch that is activated by the trunk lid opening. The pink and black wires are for the fuel cell sending unit, and the green and blue wires are for the license plate retractor motor.

I fabbed up a small bracket to mount the roller lever switch (Radio Shack PN 275-017). I used the Normally Closed output of the switch so that the switch is electrically open when the switch is mechanically closed. Route harnesses to front of vehicle. Do you remember the mess at the beginning of this project? Well, it is rapidly becoming less of a mess with each step. Group together all of the harnesses that go to the dash area and engine compartment, and route them to the front of the vehicle.

I used a 1-inch cable clamp to temporarily hold together the harnesses that go to the engine compartment and dash area. I also taped the harness in only four places so that I can easily remove this should I need to add anything along this run.

Okay, that’s a bunch of stuff. The mess that was previously on the floor is now in the front of the car. Don’t worry; I’ll soon sort it all out.

I have separated the engine component wiring from the rear, grabbed the loose sub-harnesses for the engine section and headlight sections from the kit, and routed them through the firewall.

Cable clamps provide order for your work. For now, I’ve loosely tied the harness as it goes vertical.

Pass wiring through firewall on the driver’s side. Now, I know that this is everyone’s favorite part: drilling holes. Pay special attention to things on the other side of the firewall before punching through it. Once you’ve drilled a hole, install a snap bushing or grommet (grommets of various sizes are included in the Painless kit for this purpose), and pass everything that goes to the engine compartment through it. This substantially reduces the amount of wire inside the vehicle. Don’t forget the loose sub-harnesses in the kit: specifically, the engine and headlight sections.

Even though this is a fiberglass body, always use a plastic snap bushing to protect the insulation of the wires from chafing. I used a 1-inch snap bushing so that I would have extra room should I need it (and I certainly did). Wire headlight switch. From this point forward, the bulk of wiring you have to work around is greatly reduced with each step. Take your time, and refer to the manuals as often as you need to connect things correctly.

Group all of the wiring that goes to the headlight switch, and cut it to length. Be sure to include the wiring to the headlight dimmer when you do this, as it’s easy to overlook it. The headlight switch I used was from Ron Francis Wiring, and the instructions advised to ground the switch when it is installed in a fiberglass vehicle. No problem, but that requires a female push-on connector of a non-standard size that the switch doesn’t include.

In Step 4, I added a run of wire from the rear to the front from the convenience module to the headlights per its diagram. I also interfaced the keyless entry system into this same run, as illustrated in Figure 6.6, so that the headlights can be turned on and off via the keyless remote. This needs to be interfaced to the dimmer wire for these features to work. Because the dimmer wire I need to tie into is blue with a yellow stripe, I used a pair of 16-AWG wires for this run, one yellow and one blue. Many caution you against using a pair of wires for a single circuit. The reason is that if one of the wires comes loose, the other wire has the burden of the entire load of the circuit. This was not a worry here because both headlights together only consumed 6 amps, well within the capabilities of a single piece of 16-AWG wire over this distance.

Terminating the connectors on the end of the wiring is a pretty straightforward process with an openbarrel crimp tool. Consult the headlight switch diagram when plugging the pins into the back of the connector body. To keep this straight, I found it easiest to put the plug body on the headlight switch to be sure I installed the first terminal in the correct place. I soldered a wire to the taillight wire for any illumination needs I may have that don’t require the dimmer, just in case. Also, I soldered the headlight output from the convenience module/keyless entry to the headlight dimmer wire. Wire steering column. As you complete this step, there is a dramatic reduction in the amount of wire in the front of the vehicle that you have to work around. Because this vehicle didn’t have a steering column installed in it yet, I was careful to leave the harnesses to the turn signal and ignition switches a little long. There is ample space to tie up any excess. You most likely have your column installed at this point. Use it as a reference when plugging the wires into the plug bodies, as they can be very difficult to remove if you get something wrong.

Part 3: Wire the Turn Signal Switch There are a few styles of turn signal switches. The newer GM-style switches have an input from the brake light switch that makes the turn signal switch the brains of the brake light and turn signal operation in the rear. The turn signal switch in the Flaming River column that will be installed in this vehicle is this way. If you have such a switch, the white wire from the output of the brake light switch connects to its input. If not, you have to wire your brake lights and turn signals a little differently than in this installation. Refer to the vehicle’s wiring information if that is the case, as it may differ by vehicle.

Cut the turn signal switch harness to length, and terminate the wires with the connectors included in the Painless kit. Again, pay close attention to the wiring diagram in the Painless instructions when plugging these pins into the connector body. I left myself a note so that I didn’t overlook the neutral safety switch that will be connected to the shifter.

Work in progress. Notice that the excess wire keeps getting less and less with each step.

Here is the turn signal switch connector, completely wired. Part 4: Wire the Ignition Switch The ignition switch in this vehicle is located in the Flaming River steering column. If you are using a dash- or console-mounted switch, the connectors are different. Wire dash-mounted components. Mike provided me a fairly compact aluminum mounting area that he built to fit on the dash inner structure just above the steering column. This is an ideal place to mount the ignition components, front ATC fuse panel, Painless fan controller, and front relay center. (I contacted Painless to be sure it would be okay to mount this controller near the ignition components; Painless said that it wouldn’t be a problem, but cautioned me to ground the unit in a different place than the ignition module. Not a problem.) Mike had drilled and tapped the vertical aluminum panel so that I could easily mount the relays.

Cut the ignition switch harnesses to length, and terminate the wires with the connectors included in the kit. Note that there is only one wide connector included, and it goes on the orange wire in the black plug. Carefully plug them into the connector body per the diagram in the Painless instructions.

Shown are the completed headlight, turn signal, and ignition switch connectors ready for action. A. Mount the components. Such a project can be considered a sub-project. With that in mind, I removed the aluminum mounting area from the vehicle and did a substantial amount of the work on the bench. (Hindsight being 20/20, I would have done even more of it outside of the vehicle than I did.) My only concern was accessibility of the rev chip. I discussed this with Mike, and he wasn’t worried. I drilled and tapped the lower panel for the mounting bushings for the ignition and coil, as well as another eight-position barrier strip that is used for ground distribution. I also drilled and tapped numerous holes on the underside of the panel for cable clamps, to keep things around the column in order. All holes were tapped for 10-24 screws, except those for the bushings, which are 10-32. Every serious car guy should have a good tap and die set!

My main objective here was to have ample room to run the remainder of the wiring harness behind the ignition and coil and under the relays. Because MSD recommends good airflow around its ignition module, I didn’t want to have anything on top of it. The area that this fits in has about 6 inches of space above the ignition components, and the dash sits about 6 inches forward of them, so that was not a problem.

I mounted the front ATC fuse panel on the lower side of the panel. This way, the fuses for all of the frontmounted accessories are easily accessible.

From left to right, the relays are as follows: driver’s door pop, passenger’s door pop, driver’s window down, driver’s window up, passenger’s window down, passenger’s window up, garage door number-1, garage door number-2, air conditioning, and starter solenoid. All are Tyco 30/20-amp relays, except the starter solenoid relay; it’s a 40/30-amp, easily distinguished by its metal mounting tab. Also shown is the wired barrier strip for ground distribution. Note: This vehicle does not have door locks; only door poppers (press a button and the door pops open automatically). B. Pre-wire the relays. While the panel was on the bench, I pre-wired as much of the relay cluster as I could. If I had a little more room on the bench, I would have used a few very long barrier strips to connect each wire to each relay socket. This would have greatly simplified the work in the car.

There is plenty of room around the ignition components and good room for the wiring behind them. Yeah, your workbench is going to look like this from time to time.

The relays are pre-wired as much as possible at this point. I’ve terminated the A/C power and ground leads with 10-AWG female connectors inside of a male plug body. I really like these connectors for high-current disconnects. The coiled 10-AWG wire runs to the starter solenoid, and the 18-AWG wires are for the garage door opener relays.

C. Ground the dash-mounted accessories.

It’s critical to have a good ground for all dash-mounted accessories. I ran an 8-AWG wire from the barrier strip to this 5/16-18 bolt that holds the dash structure in place. I also connected a second 8AWG wire to this same bolt, which runs through the firewall and bolts to the frame. D. Finish wiring the relays. This is, by far, the most tedious part of this project. Go through the relays from right to left, and completely wire each one per Figure 6.7 before proceeding to the next relay.

Figure 6.7. This diagram illustrates the interface between the power door poppers, power windows, their switches, and a keyless entry in this application. Regardless of the type of interface you do, the Painless 18-circuit harnesses include two separate power wires for the left and right door lock switches and the left and right power window switches (four total) to make your job easier.

After this was mounted back in the vehicle, I ran the rest of the wiring harness across it. Now begins the tedious job of connecting the wiring to the applicable relays.

Here are the passenger-side window motor relay sockets being wired.

Each door pop and window relay has a diode across the coil because they are also connected to the keyless entry system. The 18-circuit Painless harnesses include power wiring for the door pops and power windows. I used the door lock power wiring to provide power to the door pop relays.

Shown are the mostly completed relay sockets. Only the A/C relay and starter solenoid relay still have to be completed.

The amount of extra wire has been reduced. The power windows required a bit of thinking. To my surprise, the wiring for the power windows in the Painless harness was not dependent upon the ignition switch. This was ideal for my application. The Keep It Clean Wiring switches could be wired so that they triggered the relays negatively when the key was in the ACCY or RUN positions. But, the keyless entry system would need to be able to operate them regardless of the ignition key’s position, even off. In addition, the keyless entry system operates both windows simultaneously, whereas the switches operate just the corresponding window. The billet Keep It Clean Wiring switches are only capable of low current. As such, they included relay sockets and relays to operate the window motors directly. I used Tyco 30/20-amp relays instead of the supplied units. If you use traditional window switches, you still need two relays for the windows to go down and two relays for the windows to go up. Near the end of this chapter, I show you the correct interface for the Keep It Clean Wiring billet window switches so that they only operate the windows when the ignition switch is in the ACCY or RUN position. E. Wire the headlight dimmer. An option on the Flaming River column is a dimmer switch on the end of the turn signal stalk. Press the button once, and the high beams turn on; press it again, and the high beams turn off. The kit includes a small PC board that connects to the dimmer sub-harness in place of the standard floor-mounted dimmer switch.

I affixed the Flaming River dimmer switch to the mounting plate with extremely high-quality, doublestick tape. Clean surfaces with isopropyl alcohol before using double-stick tape.

Wire instrument cluster. Because Mike wanted the dash to be removable during the interior phase of the project, I wired all of the gauges via a Molex 12-pin connector kit. In addition, Mike has indicator lamps for turn signals, high beams, and brake low pressure on the dash. All of this wiring typically creates a nightmare for serviceability unless you use plugs like the ones shown in the accompanying photographs.

All of the wiring in the Painless harness specific to the gauges (coolant temperature, fuel level, volt meter, etc.) plus the wiring from the dimmer switch, headlight high beams, turn signals, brake lowpressure switch, and tachometer output of the MSD ignition box will connect to the dash via this 12-pin Molex plug. The plug has female pins in a male plug body. Cut the cluster harness to length, and terminate each wire with a female pin. Those pins are then inserted into a male plug body. Now that the cluster harness has been completed in the car, wire the actual cluster, and fit it with the mating plug. Wire the gauges per installation diagrams provided by the manufacturer.

Lay the cluster face down on your workbench to make access to the rear of the gauges easy. I labeled them from the rear so that I could easily keep things straight. In this installation, the electronic gauges are fuel level, voltmeter, coolant temperature, and tachometer. The mechanical gauges are boost/vacuum, oil pressure, and speedometer.

This is an excellent place to use butt connectors. All of the connections are low-current, and this makes things easy and quick. Start the process by connecting together the individual lamp power leads (white on these Auto Meter gauges). Then, tie together the lamp grounds, main grounds to electronic gauges, and grounds to the indicator lamps as neatly as possible. This takes a bit of thought and planning.

Finally, connect all of the signal wires to the gauges, the signal wires to each indicator lamp, and the ignition wires to electronic gauges. Tie up these wires as neatly as possible, double-checking your work, and then cut them to length.

Terminate the wires with male pins, and then plug those into a female plug body. Bring the dash to the vehicle so that you can plug the pins in the body in the correct location. Can you imagine how easy it will be to install this cluster now? But, what if your dash isn’t removable like this one? That’s okay. You’re still likely to put gauges in a common place, such as an underdash mount of some type. You can still do a bunch of work on the bench to make this easy.

Wire remaining dash-mounted components. The original plans called for both a fan-cooled transmission cooler and a fan-cooled oil cooler. The thermostats that trigger the fans are typically internal, and the wiring typically ties to a switched source of power. Mike decided that he wanted some way to manually turn them off should the need ever arise. Thus, it was necessary to install an additional pair of relays up front. No problem; the pre-drilled mounting surface and the ATC fuse panel easily accommodated this.

Adding a pair of relays here was easy. In addition, I needed to put one on each end, which I allowed for. I like it when things work out that way. Also, notice the loop of harness tied around the headlight dimmer module. This is simply some extra wiring from the harness that I didn’t need, such as power to the 4WD switch, cruise control, etc. A. Label the relays. B. Install the ignition components. Now that the relays are all wired, install the ignition components. Again, it is important to have good air circulation around the ignition box. The rubber bushings give it good isolation against vibration, as well as good air circulation under it. An MSD billet distributor magnetically triggers the ignition box, so this necessitates that the green/purple shielded harness runs through the firewall to the distributor. Other connections to the ignition box are the following:

Time to label the relays. I used 3/4-inch-wide blue masking tape for this, and then I taped over that with Scotch tape to ensure the labels stay put. All screws were installed with blue thread locker to keep them from backing out. The white wire with the red push-on connector runs between the tach output and the cluster harness.

 Ignition input (from the ignition switch). The Painless harness includes a fused power lead designed to connect to a traditional coil. I used it to power the ignition box.  The tachometer output, which I already connected to the cluster harness and ran to this area.  The main power lead. I connected this to the ATC fuse panel mounted below the plate.  The main ground lead. I connected this at the same place on the dash structure where I connected the main 8-AWG feed to the barrier strip, as well as the 8-AWG wire to the frame.  The harness to the coil. I ran this behind the ignition box and coil, shortened it slightly, and connected it to the coil. Because this ignition box has timing retard (based on boost) built in, it requires a vacuum line to the intake manifold. It comes with a dash-mounted controller that plugs into the weather-tight connector on the right of the box. Remember, the following still need to pass through the firewall:     

Harness from the ignition box to the distributor Vacuum line from the ignition box to the intake manifold Vacuum line for the boost/vacuum gauge Feed line for the oil pressure gauge Speedometer cable

In addition, you also need to drill a hole and install the MSD firewall pass-through for the coil wire.

The ignition box and coil drop right on the bushings as planned. There is plenty of room under the ignition box for the ground wiring and plenty of airflow. However, Mike has requested that I delay the previously mentioned tasks until after the engine has been installed in the vehicle. Wire plugs for console. Numerous wires must pass from the front relay cluster to the center console-mounted switches. Those include the wiring for:

 Door popper relays, power window relays, oil and transmission cooler relays, and garage door opener relays  Parking lights, dash lights, ignition, and 12 volts constant from the ATC fuse panel passes to the center console  Manual override switch for the Painless fan controller  Neutral safety switch in the shifter  Air conditioning  12-volt power point (a cigarette lighter) The console is also home to the air conditioning controls. But, because Mike hasn’t purchased the A/C kit yet, I can’t address it. But, I’ve installed a pigtail for the A/C with 10-AWG power and ground; this is more than enough to accommodate any system he buys. I used the A/C power lead in the Painless harness to trigger the A/C relay in the cluster. Note that the amount of wiring here requires numerous connectors.

On the left is the plug for the neutral safety switch; it’s a two-position, high-current connector with a male body and female connectors. To its right is the main console plug, a 15-pin Molex plug with a male body and female pins. The next one is the plug for the garage door opener relays; it’s a six-pin Molex plug with a male body and female pins. Finally, on the right is the A/C connector, another two-position, high-current connector. Only three wires are not terminated at this point: one is for the power feed for the A/C compressor and two are for the 12-volt power point. I didn’t terminate them, because Mike thinks he may choose to mount the power point up high in the console. No sense in having to cut a plug off later. Now, I can remove my reminder to wire the neutral safety switch! Pass wires through firewall, passenger’s side. There are a few more things to pass through the firewall. On the passenger’s side, those items include the main power feed from the battery to the front ATC fuse panel, the power feed for the transmission cooler, the power feed for the starter solenoid, the power and ground wires for the electric fan, the temperature sending unit wire for the Painless fan controller, and the A/C compressor power feed.

The wiring passes through the firewall on the passenger’s side. I use cable clamps again to secure everything neatly. The harness at the right is for the door lock and power window in the passenger’s door.

Route the wires neatly from the firewall to the driver’s side of the dash. I can easily relocate this harness off the ledge it is currently sitting on should the A/C unit require that space.

The wiring passes through the firewall on the passenger’s side. Again, note the use of a 1-inch snap bushing to protect the wiring. Why can’t I just ground the fan up front near the radiator? Good question. The Painless controller I’m using here actually controls the fan via its ground wire. Per the Painless controller wiring diagram, the power lead of the fan is fused and connects to 12 volts constant. This is the kind of stuff that you should be acutely aware of when wiring a vehicle. I used 10-AWG wire for all of the fans and 4-AWG wire for the main feed from the battery to the ATC fuse panel. Part 5: Wire the Engine Compartment Begin wiring engine compartment. At this point, there is no extra wiring hanging out in the interior of the vehicle. But, the engine compartment is a different story, for sure! This process is obviously easier without an engine between the frame rails, as you can get into the engine compartment and sit down for the job. Your vehicle likely has an engine in it. Remember, Mike wants me to keep the wiring out of sight as much as possible. Before I started this process, he showed me a picture of the headers he’s going to buy for this engine. They extend from the heads through the wheelwells and then go down along the outside of the frame rails. I want to stay as far away from them as I can, so I anchor everything along the inside of the frame rails.

At this point, your engine compartment should look something like this. Of course, you may also have an engine in it.

A. Route the wiring. By now, you should already have a good idea of how the process works. The first thing to do is group the sub-harnesses and loose wiring together based on the direction the wiring will be routed. Again, secure the harnesses with 3M Scotch Super 33+ tape.

Look closely and you’ll notice that I have grouped the harnesses according to the direction they’ll be routed. B. Drill and tap both frame rails for the return path. As I outlined earlier, I’m using the frame for the return path. This includes:         

Battery negative (–) Negative (–) terminal on the frame-mounted battery connector Rear ground distribution block Alternator case Engine block Bell housing Cylinder heads Dash ground Transmission cooler and oil cooler fans, the front clip harness

Again, the frame has very low resistance, so it makes a great place to tie all of these things together. Typically, I recommend using existing holes in the frame so that you don’t have to drill into the frame. This isn’t possible on a frame like this one, because it has been totally smoothed and powder-coated. Also, because it’s boxed, there is no need to worry about affecting its strength by drilling a few small holes in it.

Use a center punch to locate a place to drill. Then, drill the hole so that it can be tapped with a 5/16-18 tap. If you didn’t already know, each tap, on its shank, specifies the correct-size drill bit. After you’ve drilled and tapped the hole, use a wire brush or grinder to clean off the powder coating or paint so that a star washer will get an excellent bite into the raw metal.

Shown here is the bolt threaded into the frame rail on the passenger’s side. I terminated the ground lead of the transmission cooler fan feed with a 5/16-inch ring terminal. This bolt will be used to connect numerous things to the frame, some of which can’t be connected at this time, as the engine isn’t in the car; so, the bolt is just finger tight. I covered the bare metal with white lithium grease to keep it from rusting, and I used a 1- inch-long bolt. Finally, a star washer goes between the frame and the nearest connector to ensure an excellent electrical connection.

It’s the same arrangement for the driver’s side. Note that I didn’t wipe the excess white lithium grease off here so that you can see it. Also note that the harness coming out of the firewall is low and out of sight. For now, the bolts are installed finger tight. Down the road, when the engine is in the vehicle and I can make all of the ground straps, these bolts will be tightened with a wrench. (Buy U.S.-made bolts so that they don’t snap off.) Don’t use thread locker on these holes, because that decreases conductivity. C. Separate the harness to the front clip based on routing. At this point, you’ll be very thankful that Painless gives you all the length that you need. Divide the harness to the front clip based on right and left sides. In this vehicle, the horn is on the passenger’s side. Rather than try to ground things individually, it’s easier to run ground wires with your harnesses at this point. I used one 16-AWG wire for the driver’s lights, one 16-AWG wire for the passenger’s lights, and one 16-AWG wire for the horn. Tape the wiring accordingly.

Separate the front clip harness based on the driver’s side and passenger’s side. Notice that I’ve added the appropriate ground wires to the harness to make my job of connecting the lights and horn easier.

D. Wrap the harnesses to protect them. I covered all of the harnesses in the engine compartment with PowerBraid. This step is pretty time consuming, but using the installation tools wherever possible makes this job easier.

I neatly wrapped the harness from the firewall on the driver’s side in PowerBraid. Painless includes some self-vulcanizing tape in its chassis kit. I used 3M Scotch Super 33+ tape instead, but that’s purely a personal preference. I also used a cable clamp to keep this harness in place and close to the body. Wire front clip. A. Wire the headlight assemblies. This is a good time to ready the headlight assemblies for connection to the front clip harness. Your vehicle may have traditional headlights. This one has an assembly that houses the headlight, parking light, and turn signal in a single housing. It actually mounts in the wheelwell and not in the engine compartment. So, it’s necessary to pass through the body from the engine compartment to connect them. I removed both headlight assemblies to make this job easier. If you have traditional lighting, the Painless kit comes with brand-new GM-style headlight plugs.

Shown here is the headlight assembly from the driver’s side and the Weather Pack connectors required to connect it. The headlight has connections for low beam, high beam, and ground. The parking light/turn signal assembly has connections for parking light, turn signal, and ground. Both are dual-filament bulbs and do double-duty.

Terminating the pins for the Weather Pack connectors is really no more difficult than terminating other open-barrel pins. The main difference is that the strain relief (the mechanical crimp) also holds the rubber insulator on the wire. The MSD crimp die made this a snap, because it does both the mechanical and electrical crimp simultaneously. Once the pins have been installed, simply slide them into the rear of the plug body and snap the lock closed.

I drilled a 1/2-inch hole in the body and passed the wiring through for the headlight assembly. With the headlight assembly out of the way, it was easy to terminate the harnesses. I installed the plugs so that they can only be plugged in one way. Your vehicle may also have separate bulbs for high and low beams. However, most vehicles have a single housing that serves the parking lights and turn signals via a dual-filament bulb. Finally, you may also have side marker lights that are tied to the parking lights. Either way, the Painless harness allows you to connect everything properly. This is really very simple. Because these housings are in the wheelwells, I used GM Weather Pack connectors to make these connections. These are readily available from Painless, MSD, and others. Also, I picked up a set of Weather Pack crimp dies from MSD (PN 3509). I covered the harnesses for the headlight assemblies and the wiring in the wheelwells with PowerBraid to protect them from water and debris being flung up by the tires. Repeat this process for the passenger’s side.

B. Wire the horn. This was a no brainer: one terminal to the green wire in the Painless harness and the other to ground. Good thing I ran that 16-AWG ground lead; that made this job a snap. Anchor wiring harnesses to frame.

Route the PowerBraid-covered harnesses along the frame rail to the front clip. The ground connection for the front clip is to the left of the radiator on the frame rail. The harness is low, out of the way, and held in place with some trusty cable clamps.

Use cable clamps to hold the harness up and out of the way, using pre-existing bolts wherever possible.

I routed the harness across, just in front of the radiator. Another cable clamp keeps it up and out of the way of moving parts, as well as out of sight.

The PowerBraid is tedious to install, but you can’t argue with the finished results. Shown is the harness to the electric fan, terminated with the matching high-current connector; the harness to the left side of the engine; and the transmission cooler fan harness.

Here are the oil cooler fan harness and the harness to the right side of the engine.

If you take your time, your installation will look this clean, too. Wire battery. Surprised to see that these are the very last steps? Well, why wouldn’t they be? After all, you don’t need the battery to be wired up during the rest of this installation.

Working with large cable requires a bit of planning. After all, a short can cause as much as the CCA rating of the battery to flow; that’s a bunch. Your application is undoubtedly different from that shown here, but the procedure is the same. All cable assembly steps shown here are via the crimping press. If you don’t have access to such a crimp tool, then you can always use a propane torch and solder the lugs. Never use a hammer or bench vise for these. A. Make up the cables. Here are the cables you need to make for this application: Positive (+)   

Battery positive (+) to circuit breakers, 1/0 AWG Circuit breakers to battery positive (+) terminal on frame rail, 1/0 AWG Battery positive (+) terminal on frame rail to front-mounted distribution block, 1/0 AWG

Negative (–)   

Battery negative (–) to frame rail, 1/0 AWG Frame rail to battery negative (–) terminal on frame rail, 1/0 AWG Frame rail to main ground distribution block on rear dividing wall, 4 AWG

Use the fabrication method described and illustrated in Step 4 of Project 9 in Chapter 5. B. Install the front power distribution block. Obviously, I’m mounting a second distribution block under the hood; it’s another Rockford Fosgate RFD1. The distribution block is easy to access. In addition, it is easy to connect the 4-AWG power wire to the starter and the 4-AWG charge lead from the alternator. The distribution block provides an easy place to connect all of the large-gauge positive (+) cables for the charging system and starter. The 1/0-AWG wire from the battery connects to one side of the block, and the other side of the block accommodates a 4-AWG power wire, to feed the starter, as well as a 4-AWG charge lead from the alternator. A junction stud could be used here, as well, but the distribution block is easier to install and much neater.

Install the front distribution block. I used a Rockford Fosgate RFD1. Connect a run of 1/0AWG wire from this block to the positive (+) battery terminal along the frame rail. Use cable clamps to secure this run, as well as the 4-AWG run that feeds the interior ATC fuse panel. I wrapped it with PowerBraid and terminated that with heat-shrink tubing to give it a nice finished look.

C. Cover, route, and secure the cables.

Run the 4-AWG wire and 1/0-AWG wire along the inside of the frame rails, and use rubber-lined metal cable clamps to secure the runs. I didn’t have enough PowerBraid to cover these lengths fully, so I used traditional split-loom tubing under the vehicle where it couldn’t be seen. I joined them with heat-shrink tubing.

This is the battery connection point that Mike installed along the frame rail. This allows him to charge the battery easily or jump-start the vehicle in the event that the battery dies. These are 3/8-16 studs, so I had to drill the JL Audio ring terminals to fit them. Note the use of rubber-lined metal cable clamps to keep everything neat and out of harm’s way.

Here, the cables are shown passing over the rear frame rail. They are not tied to the fuel line. It goes without saying that the ground connection from the battery negative (–) terminal to the frame rail is an extremely important electrical connection. Use high-quality bolts and washers to ensure that you can get it nice and tight. Also, the paint or powder coating must be removed down to the bare metal. Use a star washer and lithium grease to promote an excellent trouble-free electrical connection to the frame.

The cables pass through the floor to the battery via 1-inch snap bushings to protect them. The frame has been drilled and tapped for a 5/16-18 bolt for the grounds. This is the main ground; be sure it’s nice and tight so that it doesn’t come loose. Check this from time to time to be sure that it stays nice and tight.

The cables come up through the body. Between the snap bushings and the split-loom tubing, these cables are well protected. From left to right are the vent for the battery box, the 1/0-AWG power cable that connects the circuit breakers to the starter and alternator, the 4-AWG power cable that feeds the front ATC fuse panel, the 4-AWG ground cable that connects to the rear ground distribution block, and the 1/0-AWG ground cable that connects to the battery negative (–). Be sure to use grommets or snap bushings when passing wire through the body or the firewall to avoid damage to the insulation of the cables. I always recommend looming or sheathing large power cables to protect them from debris. Finally, use rubber-lined metal clamps to anchor them in place along the frame rails and out of harm’s way. Connect circuit breakers and rear ground distribution. I installed the Rockford Fosgate 200-amp circuit breakers on the rear dividing wall and re-installed the JL Audio fuse holder that I removed previously to make way for the high-current ground barrier strip. The purpose of the circuit breakers is to protect the 1/0-AWG cable from a dead short along its route from the battery to the front of the vehicle. None of the aftermarket battery relocation kits includes any kind of protection for the positive (+) cable, but I won’t take that risk. No worries; these won’t flip open when you’re leaning on the starter.

The 1/0-AWG power cable is routed to the circuit breakers, which are wired in parallel. I had to modify the ring terminals slightly to get them to fit on these breakers. They are labeled BAT (battery) and AUX (load). Be sure to wire them accordingly. The 4-AWG power cable is connected to one end of the JL Audio fuse holder. Finally, the 4-AWG ground cable is connected to the rear ground distribution block.

The 1/0-AWG cable from the battery side of the breakers connects to the battery positive (+) terminal. I’ve connected the power side of the JL Audio ANL fuse block and the rear-mounted ATC fuse block to the battery side of the top circuit breaker. I used blue thread locker on the hex screws for the JL Audio fuse holder to ensure that these cables never come loose. Finally, I connected the main power feed to the Painless Maxi fuse holder to the battery side of the bottom circuit breaker. Install battery box and battery. Mike had already drilled holes in the body where he wanted the battery box to be. All I had to do was install it. The kit from Taylor included everything I needed, which made this step a snap. Due to good planning, the XS Power S3400 battery was a perfect fit.

Drill two 3/8-inch holes in the floor of the body (use the battery tray bottom as a template). Because this is a fiberglass body, Mike will add a 2-inch-wide metal strap secured by the bolts beneath the floor to increase strength. Before locking down the battery, cut the threaded rod to the correct length so that the acorn nuts properly hold the battery box top in place (seen in the instructions provided by Taylor).

The 1/0-AWG battery cables are installed, as well as the slick JL Audio battery clamps (see sidebar “Battery Clamps: Advancing Technology” below). I drilled two 1-inch holes and installed 1-inch snap bushings to accommodate the 1/0-AWG cables. When the audio system is installed, it will require a 4AWG power cable to feed the amplifiers. That will route through the stock rubber grommet in the Ugroove on the left. Incidentally, the ground cable for the amplifiers connects to the spare terminal on the rear distribution block. Battery Clamps: Advancing Technology These battery clamps from JL Audio are really handy when you need to connect multiple large-gauge wires safely to either battery post. They are compatible with either positive (+) or negative (–) battery posts (the negative post is a smaller diameter). I use aftermarket battery clamps often in projects like this for several reasons. First, I like the flexibility they offer; these clamps easily accommodate three large-gauge cables of up to 1/0 AWG each. Second, your local car stereo retailer typically has a wide variety of them in stock. Last, most aftermarket battery clamps have some kind of plastic cover included or available as an option, and I’m a big fan of those. If you use these clamps in a high-vibration application, such as a race car, use thread locker to keep the set screws from backing out. Tighten them very securely to keep them from ever working loose.

This JL Audio battery clamp offers a lot of installation flexibility. I set up the rear insulator so that it would accommodate a 4-AWG wire on the left and a 1/0-AWG wire in the middle; I plugged the right with a blank.

Part 6: Wire the Interior Lights Build circuit for interior lighting. Now, don’t worry, this step is actually pretty easy. The objective of this circuit is to turn the interior lights on when either of the doors is opened. This is commonly referred to as a closed-loop circuit, while a normal pin switch is an open-loop circuit. Earlier in the project, I created a loop on each of the door pin connectors. That loop is “in circuit” when a door is closed, and it isn’t when the door is opened. It should be obvious by now that you have to connect the loop on each door in series with one another, because we want the lights to come on when either door is opened. A. Obtain the parts. As I stated before, all of the parts are available at your local RadioShack. Here are the parts required:        

(1) 276-563 12V zener diode (1) 276-2072 IRF510 field effect transistor (FET) (1) 272-1053 .1μF capacitor (1) 271-1118 1kΩ 1/2-watt resistor (five per pack) (1) 271-1131 100kΩ 1/2-watt resistor (five per pack) (1) 275-248 10A relay with 12 VDC coil (1) 276-0148 PC board kit (1) 270-1801 project box

You also need a six-pin plug of some type if you want to make it plug-and-play, but that isn’t necessary. You could just as easily use a barrier strip to connect to it. I used a six-pin plug, also obtained at RadioShack. Figure 6.8 is a diagram of this circuit. B. Build it. I had to trim the PC board a little bit with a bench grinder to get it to fit into the project box (it’s weird that RadioShack doesn’t sell an exact-fit board). I also drilled the holes slightly so that I could screw it into the box. Before mounting the board in the project box, it’s a good idea to test it. To do so:  Strip the ends of all five wires, and twist the two 18-AWG white wires together.  Connect the red probe of your digital multimeter to the 16-AWG white wire, and connect the black probe to the black wire; set the meter to read continuity, and turn on the audible beeper, if it has one.  Grab a good 9-volt battery, and connect its positive (+) post to the red wire and its negative (–) post to the black wire.  Disconnect the 18-AWG white wires.  The relay should click, and your meter should show continuity. If so, congratulations; the circuit works as it should. If not, double-check all of your work to be sure that you connected things correctly, and re-test.

Figure 6.8.

Here are the parts required. The relay I used is slightly different than the RadioShack version in the parts list; I just had it lying around. Also, the resistors are not pictured.

Shown is the assembled circuit. Take your time, and pay very close attention to the diagram. I used 18AWG stranded wiring, but 18-AWG solid wiring would have been much easier to get through the holes in the PC board, which is available at RadioShack.

Here is a side view. I marked the common on the relay with a “C” to keep things straight. I secured the relay to the PC board with double-stick tape and used a small wire tie to hold it in place permanently.

Here is the bottom view showing the actual solder connections. Just push your wires through, and use needle-nose pliers to twist them together. Solder them, and then cut off the excess with some small diagonal cutters.

The PC board is mounted in the project box. You have to lean the FET over to get the lid on.

The completed box with the plug terminated on the wires. I used a 1/2- inch snap bushing where the wires exit the box to protect them. This circuit draws very little current at idle (with the doors closed). I measured 130 μA; yes, 130 microamps. C. Install it. Earlier, I terminated the harness in the car with the mating six-pin plug, and I plugged in the module. I then temporarily connected a small light bulb to the dome light wiring in the rear console plug. I opened and closed both doors, and it worked like a dream. I then mounted it just above the Painless fuse panel.

The interior light module is completed. I cleaned this area with isopropyl alcohol and used high-quality double-stick tape to mount it. Part 7: Wire the Windows

Wire switches in center console. There are a bunch of switches to wire. Many are simple SPST and switch only ground or switched power. Some are lighted; others are not. (You know all about switches, though, so I won’t bore you with the exact interface between each one and the accessory it operates.) The Keep It Clean Wiring billet switches required a bit of thinking. Remember that I left the exact interface for later? Figure 6.9 details it. Mike threw me a bit of a twist here. The switches he purchased for the windows are two-color units, and he wanted them to illuminate one color (blue) when idle and the other color (green) when in use. They’re super slick, actually; each has an LED-lit trim ring around the switch. But, beware, they included no wiring diagram. I quickly verified that the middle three pins are for the switch (SPDT) and that the outer two pins are for the illumination.

Figure 6.9. So you’d like to use some billet Keep It Clean Wiring two- color LED switches for your power windows and you want them to illuminate one color when they’re idle and another color when they’re in use? This diagram shows you the specifics. This is the kind of stuff that separates the neat cars from the really cool ones. I contacted The Hoffman Group (parent company of Keep It Clean Wiring) in an effort to obtain some wiring information on the two-color LED. I was advised that if I connected 12 volts to one side of the LED and connected ground to the other side, the LED illuminates in one color. If I reverse these connections, it illuminates in the other color. I verified this with a 9-volt battery and a few alligator-clip leads. Unfortunately, the company was not able to provide an easy interface for this, so I designed the one you see in Figure 6.9; it was actually quite simple. Part 8: Complete Wiring to Center Console

Now it’s time to drop in the center console and complete the wiring to it. The owner hired an interior fabricator to make a mock center console so that I had a temporary place for the switch panels and components. The console itself will have to be modified to fit the theme of the interior. All of our hard work will pay off in spades here as I’ve built everything to be plug-and-play. This greatly simplifies things in an installation of this scale.

The owner’s interior fabricator mocked up the structure for the center console. Even though a bunch of Keep It Clean Wiring billet switches is called for, he did an excellent job of keeping the overall look simple. After wiring the switch panels, connect them to either the front or rear Molex plugs to complete this part of the job.

I used my handwritten notes as a guide to wire the switches. This process takes a bit of time and patience. Notice that I use heatshrink tubing to insulate each electrical connection.

Terminate Molex plugs on the wires accordingly. Notice that I’ve taken my time here so that this is totally plug-and-play.

This is the completed front switch panel assembly from the rear. The plugs on the left connect to the plugs from the dash area. The large plug on the bottom right connects to the plug from the rear relay center. The light green wires are for the back-up light switch on the shifter and the white/black wires are for the interior lighting that will be mounted in the console. The plug at the far right connects to the rear switch panel assembly. Finally, the four-pin plug at the right of the switch panel has 12VDC constant, 12VDC accessory, parking light, and dash light connections making the addition of future low-current accessories a snap.

The rear switch panel assembly came out really nice. The window switches are wired per the diagram in Figure 6.9. As you can imagine, this took several hours to complete.

This is the completed rear switch panel assembly. The plugs on the left are for the power seats, the plugs at the top right for the garage door opener remotes (to be located near this panel in the console), and the plug at the bottom right connects to the front switch panel. Both panels are totally plug-and-play; very serviceable!

Disassemble the garage door opener remote control (in this case, a Genie). On the rear of the printed circuit board, locate the connections to the transmit switch. Use your DMM to determine the correct connections to duplicate the function of the switch. Solder a length of 18-AWG wire to each. You can test the opener by shorting these wires together; the remote should transmit.

Drill a small hole in the case of the opener remote to allow the wires to pass through.

I chose to terminate these wires with a 2-pin Molex connector so that it could be unplugged easily and removed should the unit ever need the battery replaced.

Plug in the front panel and verify operation of all of the switches. Notice that I labeled each of the plugs clearly. The shop can plug it all in easily and correctly when they finish the console.

Although quite difficult to capture with a camera, this photo gives you an idea of how awesome these switches look when illuminated. Note that each is etched based on its application.

Window switches light up blue when idle and change to green when pressed. This subtle touch is very cool!

Part 9: Last-Minute Details I received the Painless fan controller and convenience module in time to install them before the book went to press.

Because I pre-wired for the controller, installation was a snap. Note that I installed it in such a way that the fan speed settings are easily accessed, even after the dashboard is in place.

The Painless convenience module and installation was also easy thanks to my pre-wiring. Part 10: Test Everything

The rear dividing wall after the installation was completed. After wiring the myriad switches, connect their outputs to either the front or rear 15-pin Molex plug to complete the job. After you’ve completed an installation such as this one, you will undoubtedly think of something that you overlooked or would like to change in some way, typically after a few days have passed. It’s normal. But this is where your efforts in serviceability pays off. Verify operation of all circuits of the main fuse panel. A. Connect the battery, and check all of the common vehicle functions handled by the Painless fuse panel, including lights, turn signals, ignition switch, dash lighting, air conditioning, wipers, neutral safety switch, windshield wipers, and radio. B. Use your DMM to determine current draw on the battery (this process is outlined on pages 34 to 36 of Automotive Wiring and Electrical Systems). C. With all of the accessories off and the doors closed, you should read less than 50 milliamps of current draw, preferably less. Only after you’ve verified that every circuit in the main fuse panel works correctly, and that there is no appreciable draw on the battery with everything off, should you proceed to check secondary fuse panels. Verify operation of all circuits on any auxiliary fuse panels. Be sure to install any main-power fuse that protects the power feed to them first (such as the JL Audio fuse holder in this car). A. Insert one fuse at a time into any secondary ATC fuse panel, and check that circuit and that circuit only. Once you’ve verified that it works correctly, move on to the next circuit.

B. With all circuits tested and working correctly, repeat Parts B and C from Step 1. This was a massive project, and it took a great deal of time to complete (three weeks, in my case). If you take your time and complete one sub-project entirely before proceeding to the next phase, a big project like this one goes quite smoothly.

SOURCE GUIDE AutoMeter 413 West Elm St. Sycamore, IL 60178 (866) 248-6356 www.autometer.com Automotive Diagnostic Specialties 6835 W. Chandler Blvd. Chandler, AZ 85226 (480) 961-8704 www.adsautorepair.com Beck Racing Engines 2639 N. 33rd Ave. Phoenix, AZ 85009 (602) 477-1700 www.beckracingengines.com Fluke Corporation 6920 Seaway Blvd. Everett, WA 98203 (425) 347-6100 www.fluke.com FutureVisionHID.com (204) 371-7311 www.futurevisionhid.com Holley 1801 Russellville Rd. Bowling Green, KY 42101 (270) 782-2900 www.holley.com Infinity Box Intelligent Wiring 1410 Brummel St. Elk Grove Village, IL 60007 (847) 232-1991 www.infinitybox.com Iraggi Alternator (615) 287-7991 (615) 594-8965 www.iraggi-alternator.com JAZ Products

1212 E. Santa Paula St. Santa Paula, CA 93060 (800) 525-8133 www.jazproducts.com JL Audio, Inc. 10369 N. Commerce Pkwy. Miramar, FL 33025 (954) 443-1100 www.jlaudio.com Koul Tools 2447 Wood Ln. Lake Havasu City, AZ 86406 (928) 854-6706 www.koultools.com MagnaFuel 615 Wooten Rd., Ste. 120 Colorado Springs, CO 80915 (800) 321-7761 www.magnafuel.com Mechman 7501 Strawberry Plains Pike Knoxville, TN 37924 (888) 632-4626 www.mechman.com Mitchell 1 14145 Danielson St. Poway, CA 92064 (888) 724-6742 www.mitchell1.com Motor Mike, Inc. (480) 963 5885 www.motormikeinc.com MSD Ignition 1490 Henry Brennan Dr. El Paso, TX 79936 (915) 857-5200 www.msdignition.com Nitrous Outlet 5387 N. Hwy. 6, Ste. 101 Waco, TX 76712 (254) 848-4300

www.nitrousoutlet.com Painless Performance Products 2501 Ludelle St. Fort Worth, TX 76105 (817) 244-6212 www.painlessperformance.com Prestolite Performance Mr. Gasket Company 10601 Memphis Ave., #12 Cleveland, OH 44144 (216) 688-8300 www.mrgasket.com Rockford Fosgate 600 S. Rockford Dr. Tempe, AZ 85281 (480) 967-3565 www.rockfordfosgate.com Ron Fassl and Sons Automotive 7117 E. Angus Dr. Scottsdale, AZ 85251 (480) 945-0494 XS Power Batteries 2847 John Deere Dr., Ste. 102 Knoxville, TN 37917 (888) 4XS POWER www.xspowerbatteries.com Year One P.O. Box 521 Braselton, GA 30517 (800) 932-7663 www.yearone.com

ABOUT THE AUTHOR Tony Candela has been in the automotive aftermarket electronics industry for more than 25 years and has held positions in installation, sales, management, manufacturer’s sales representation, and regional sales management. In his tenure, he has worked for two aftermarket electronics manufacturers: Clifford Electronics and Rockford Fosgate. In February 2009, he founded his own company, Candela Sales & Marketing, which specialized in the automotive and electrical fields. In April of that same year, his first book, Automotive Wiring and Electrical Systems, was published by CarTech. In 2011, Tony founded CE Auto Electric Supply, a supplier of automotive electrical components, and in 2014, he penned the book EFI Conversions: How to Swap Your Carb for Electronic Fuel Injection, also for CarTech. Tony has written about and given hundreds of seminars on the topics of installation, application, wiring, and basic automotive electronics. On the weekends, he can typically be found in his garage working on his vehicles or at any number of car gatherings in the Phoenix area.