Wiring for Reliability

Mark Stielow's Malitude Gets One Step Closer to the Road

Mark Stielow Mar 17, 2005 0 Comment(s)

Wiring a vehicle is like bringing it to life, providing veins and capillaries for its electrical lifeblood. Imagine if someone did a crummy job of laying out your veins in your own body? Now, we're not looking to get into a religious argument here, but you get my point--treat the project car and its wiring like it's truly yours and you'll work that much harder to get it right!

My Malibu with attitude that I'm calling "Malitude" is getting that much closer to hitting the street, but I still don't I enjoy this particular step. There's a lot of attention to detail and it's very black and white--it works or it doesn't. If it all works, it is a great feeling. But, if you turn on the wipers and nothing happens, you have to start troubleshooting. Is the wiper motor bad? Is the switch bad? Did I wire it wrong? It can be hard to tell, but you still have to figure it out.

That's why I like to do one system at a time and check the functionality as I go. It makes it easier to troubleshoot and keeps you motivated with many small victories along the way, instead of facing frustration. I like to start with the easy stuff, like getting the lights to work. It's nice to be able to hit the turn signal and see the light flash, an affirming move to reinforce you know what you're doing. Just as when I did this in my home shop, say, "Okay, now that works, so let's get after the more complicated stuff," and check out the meat in the captions.


The first thing that you need to before you start wiring up your project is to get a game plan. With this project we're going to use a Painless Performance Parts wiring kit (PN 20102) for the main wiring of the car. But, this car also has electronic fuel injection, electronic transmission control, air conditioning, an audio system, a variable speed wiper motor, and all aftermarket gages. And, all of the suppliers have their own wiring strategies and wire color scheme! Pick one main wiring schematic and add and subtract circuits as needed. We're following the Painless system for our main wiring color coding.

The tools for this job are straightforward and most hot-rodders already have them. You'll need a good pair of wire strippers, wire cutters, a soldering iron, wire crimpers, and a heat gun or a simple cigarette lighter. Most kits are designed to use crimp connectors, but I don't recommend using them. It only takes a little more time to strip the wire solder and then cover it with some heat shrink tubing. With a little practice your work will look very professional and last for years.

Over the years I've learned that one of the areas that can get very busy and messy is business inside the dashboard, especially with a complement of aftermarket gages (I use and prefer Auto Meter's stuff). Each gage needs its own switched 12 volts, ground, and dash light power and I have found it easiest to wire the dash out of the car on the bench. If you follow the color codes on the Painless wiring schematic, it will be easy to keep the circuits correct when the dash finally goes into the car. I like to run all the dash wires to a large connector so it's easy to remove and install the dash for future service.

On the dash and in the engine harness there are many items that need either a common power or ground. I like to use one common wire and splice all the other leads onto that wire. Strip the primary wire by using an Exacto-style blade to circumferentially cut the wire in two places were you want to strip it. Longitudinally cut the insulation on the wire between the two circumferentially cuts. Strip the insulation off the wire. Then strip the insulation off the end of the wire that you want to add in.

Twist the lead onto the primary wire. It's easy to be sloppy here, but take your time and get it looking similar to this. If you don't have enough wire to make them wind together cleanly, then you didn't strip enough in the first place.

Now is the time to solder the joint. As I said before, many of you find this to be a pain, but because we're wiring on the bench and not in the car, the soldering process isn't messy.

Cover with heat shrink tubing and add heat. This is the simplest part but gives you the trick look. Not only will you drive around knowing that your stuff was done correctly and won't fail, but when you go to sell your car and a qualified browser looks at your detail work, you'll have a better chance to get the money you were hoping for with details like this in place.

Before you start placing the main body harness in the car, all electrical devices need to be mounted in the vehicle. Trust me, it's much easier to get everything in the car or have it mounted so it can be easily remove and replaced before you start wiring. It's really depressing to have to rip you nice wiring apart to add a circuit in later.

I like to spread out the harness and add on a system at a time on the bench. Here, I have the whole Painless body harness stretched out. It's easier to work on, and if you terminate the harness for larger systems, like the dash, you can work on them one at a time. I'll have the harness in and out of the car multiple times to verify things fit and the wires are the correct length.

The center of the Painless body harness is the fuse block. The great thing about a Painless kit is that it comes with all the circuits you'll need--that seems like a no-brainer but I've found other kits to be lacking in the detail department. If you were to try to retain the OEM harness, you would quickly run out of capacity for all the features of a modern hot rod.

A real timesaver came with the purchase of a reproduction light harness, like the front and rear harness from Original Parts Group (PN 05745 & PN 07180). The only thing to watch out for is that the Painless color-coding is not the same on all wires as an OEM harness for the '60s. The great thing about the reproduction harness is that the connectors are all brand new and the harness fits right in the car, including the factory clips that route the harness.

Here is an example of every part having its own wiring diagram. In the case of the Ididit column, its wire color-coding matched the Painless kit and it was very easy to hook up using their connector and terminals.

The terminals are the original OE type and should be crimped with the correct crimpers (pictured). These are available from Wires and Pliers or any good electrical supply house. If you don't have the correct crimpers, just crimp the best you can and then solder the connection.

I added a Detroit Speed Selecta-Speed windshield wiper motor to this project (PN 121601). Again, it comes with its own standalone harness that can be easily installed just using a power and ground, or you can integrate it into your harness with some care. These are cool because they allow you to have intermittent wipers like a new vehicle. The kit is very complete and it bolts right on.

Because these old cars only have one small taillight, I decided to add LED taillight bulbs to make the brake and turn lights brighter. These bulbs are a direct replacement for the OEM bulb and are available from Everglades Performance.

Everglades also sells a HID headlight kit for these cars that I also install to brighten up the front.

I enlisted the help of Mike Brown from Wires and Pliers to build the engine harness for the Electromotive EFI system that will feed the twin-turbo big block that powers Malitude. Mike builds ultra-cool engine harnesses that are enclosed in Raychem heat shrink tubing like an Indy-car race harness.

The engine side of the harness terminates into a MIL-spec 42-pin connector in the firewall. Mike also built the harness that connects the FAST transmission controller for the TCI 4L80E (the tranny controller needs many of the same inputs that also run to the EFI controller).


Auto Meter
Sycamore, IL 60178
TCI Automotive
Ashland, MS 38603
Painless Performance Products
Ft. Worth, TX 76105
Electromotive, Inc.
Manassas, VA 20110
Everglades Performance Engineering
Pompano Beach, FL 33069
Wires and Pliers
Brighton, MI 48144


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