Wiring harness type

Replacing an entire harness is the fastest and easiest way to do the repair, and is what most conscientious mechanics will do on a customer's car to insure the quality of the repair, but it is not the only way. For the type of damage you described, it is just as acceptable to replace each wire individually.

A perfect example of this is when the wires break between the door hinges. I repaired a half dozen Dodge Caravans for this when working for a very nice family-owned Chrysler dealership in the 1990's, (right before I too became a teacher at my local community college). These vehicles were always a good eight to ten years old, so they were well out-of-warranty. At most, they would have 22 wires running between the driver's door hinges. To replace the broken ones, plus all of the others at the same time, took about two hours and 40 feet of wire. At the labor rates back then, the total bill would be around $150.00.

Now, if the customer got talked into buying an extended service agreement, (which my dealer never pushed on people), that repair would be covered, but the warranty company required us to replace the entire harness, like you're wanting to do, again, to insure the quality of the repair. This required pulling the driver's and front passenger's door panels off to unplug the power lock and power window switches and motors, the power mirror switch, the speaker, and the courtesy light, etc. The steering column had to be lowered to pull the entire dash board assembly back, as that harness ran from side to side right under the lower edge of the windshield. On both sides, a 2"-square plug had to be fished through a 1"-square hole to reach the fuse box and another connector. The harness went up the right "B"-pillar to the sliding door power lock contacts, and under the carpet to the drawer light under the passenger's seat. That entire harness cost the warranty company over $1000.00, and the best I ever did, with experience, was over six hours to complete the repair.

We were reimbursed only four hours for the repair, so I worked two hours for free. My dealer made up the difference for me, but he wasn't obligated to do that. That is part of the cost of being a mechanic. The customer usually had to pay a $50.00 deductible, but they also paid up to $1200.00 for that service contract. For many of them, that was the only repair they ever needed that was covered by that expensive contract, so they paid up to $1250.00 to have the wiring harness replaced. Now you run the risk of a forgotten screw or mispositioned bracket in the dash, and a resulting squeak or rattle. Some other wire harness could get tugged on to the point it is laying over the sharp edge of a metal bracket, and vibration will cause it to rub through and short out months or years from now. A heater control cable might rub or bind and not move fully to one side. There's all kinds of problems that could be unintentionally introduced.

Compare that to the $150.00 the customer would pay for the faster repair. Nothing goes wrong with the rest of the harness, so it is not always the best choice to replace it.

The most efficient repair for your truck is when you can find a connector on either side of the fire damage. There is typically a colored locking wedge that must be pried out, then you can bend a plastic finger to allow the terminal to be pulled out. I do the repair by cutting the wire, leaving 1/8" of it on the terminal. Pull that 1/8" of insulation off, prepare the new wire the same way, slide the wire strands together, then solder them. Poke down any sharp points of wire that are sticking up before you solder them. That ball of solder must be small enough so you can slide the terminal back into the plastic connector body.

The wires you use should be the same length and the same gauge, but they don't have to be the same color, especially if this was a custom harness. If you really want to maintain the same wire colors, you definitely will not find spools of original colors at any auto parts store. They have the standard black, white, light green, dark green, etc. Domestic car manufacturers use a solid color with a different color stripe, or "tracer". Import manufacturers use a solid color with a combination of different color stripes, dashes, and dots. The only way you're going to find those colors is to pull some harnesses from vehicles in a pull-your-own-parts salvage yard. Look for sections of harnesses that don't move, meaning avoid harnesses from door hinges, hoods, and deck lids, and things like that. No sense using wires that are already weak from repeated flexing.

Another way to do this is to just cut a melted wire on each end where it is still okay. Don't twist the wires to splice them like we do with house wiring. Instead, slide the strands into each other, press any sharp points down, solder the splice, then seal it with heat-shrink tubing with hot-melt glue inside. That will seal out moisture and prevent future corrosion. Never use electrical tape on a car or truck. That will unravel into a gooey mess on a hot day.

I was a tv / vcr repairman since the early '70s, before heat-shrink tubing was around, but it wasn't until the mid '90s that I learned about the stuff with the hot-melt glue inside. We got that from Chrysler and it was quite expensive. Today you can find it at any auto parts store for reasonable cost. The glue will ooze out when you heat the tubing. That glue will seal the splice from moisture and corrosion.

You said that wrong. "He's the brains and you're the good looks!"

The best approach is still to find something similar in a salvage yard, even if you have to pull off more than you need. New harnesses from the dealer are horribly expensive, if you can even still get it, because each one is hand-made. It's common for one to cost way over $1,000.00.

All you need to start with is a representative harness. It might not have every wire, but we can try to figure that out later if we have to add any. If you pull additional harnesses from another truck, you can take out the individual terminals with their wires to add into the harness you're installing.

Say, for example, your truck was available with or without cruise control. Most manufacturers will produce a harness without the one or two wires for that system. That saves them a few pennies on the cost of the wire and terminals, but the plugs will be the same. They might have to stock two, three, or four variations of that harness, but once they're sold, that is no longer a problem. A few manufacturers will only produce one harness that already has every wire for any combination of optional equipment that was installed. Those are less common. We don't often find a wire in a harness that doesn't connect to something on the other side of the connector, or connects to nothing. That reduces the number of part numbers they have to keep in inventory, but each one costs a little more to make. Believe it or not, if they can find a way to save five cents on the cost of building a vehicle, that makes real big new in the factory, and can translate into a few hundred dollars in the cost of that vehicle by the time it reaches the dealer.

If you have a copy of the manufacturer's service manual, that will have a section that shows most connectors and the wire colors and functions associated with them. The problem is you might only find connectors that plug into items like computers and sensors. Often they do not show connectors that just connect one harness to another, such as when connecting an engine harness to a body harness. That type is only needed when putting the truck together on the assembly line. They usually aren't needed after that, so you can bypass them if you want to. Bulkhead connectors are almost always shown.

If you mean "Pull-A-Part", there's three of them there, and I've been to all of them. Been to 16 of their yards between Ohio and southern Georgia. Always came home with good deals.