Simple Ways to Clean Up and Protect Your Racecar’s Wiring

Most NASA competitors are DIY folks. We build and maintain our own racecars and take enormous pride when those cars hit the track. But, just because we can do “most” of the work on our cars, doesn’t mean we are experts on every system in a racecar. For a lot of racers, electronics are intimidating. Most racers I know hate anything that deals with wiring. For some of us, wiring just looks like spaghetti. In reality, the underside of a lot of racecar dashes does resemble spaghetti, which can short out, cause a fire and ruin your race.

Nobody wants to have 10 cents worth of vehicle wiring ruing their chances for a victory at the track. The trick is to take the time to wire your racecar and its accessories in a way that under race stress — vibration, heat, water exposure — your wires won’t short out and cause an issue. This can be done with planning, patience and a few accessories.

Our team started using mil-spec wiring harnesses from Chandler Autosport for our engine bay, which inspired us to step up our game in the wiring department for the rest of the car. Here’s how we upgraded some of the harnesses on our car.

When looking at Chandler Autosport’s harness, we saw how it was neatly organized, color coded, the perfect length, and easy to use. We decided to steal the same ideas and fix other wire looms in our racecar.

This is a familiar scene in a lot of racecars: unprotected wires all over the place, taped together with masking tape. It looks bad because it is bad. We are going the clean this up the right way.

To move on from the spaghetti-wiring, fire-hazard scenario to a more professional approach doesn’t take a lot of money or knowhow. It comes down to a few accessories you can pick up on Amazon and a couple of hand tools. One of the ideas we stole from Chandler Autosport was the expandable wiring sheath it uses to hold wires together and protect them from outside influences.

For less than $40, I ordered all of this wiring harness goodness from Amazon and it was delivered to my front door on a Sunday. Yes, a Sunday. What a time to be alive. I scored some multi-colored wires, a wiring sheath, a ton of shrink0 wrap and some wiring eyelets and connectors.

Before I jumped off a cliff constructing my own custom wiring harness, I decided to take on something simple, something that made sense to my dumb racecar driver brain. So, I decided my first project would be a ground wire. I knew where it started and I knew where it ended. It was something I didn’t think I could screw up while testing my skills at some wiring clean-up.

Our Honda Challenge Acura Integra had a stock ground strap that had seen better days. It looked bad, and it was probably going break eventually under race stress. We decided to replace it, and we wanted the new ground strap to match the Chandler Autosport design.

The first step was to remove the old beat up ground strap so we could ensure the new ground strap was built to the correct length. Then we grabbed all of our new supplies from Amazon and a few tools (wire cutter, wire crimper, scissors, wire stripper, and small torch) and got to work.

Our first attempt at playing with the ground strap was not what we wanted. It was too long and we forgot to put on the sheath covering before the shrink wrap. Not a big deal. We could still salvage this piece of wire by cutting off the ends and starting over. During the second attempt, we were more careful with the order of operations.

We learned quickly that there is an order to how you do things when it comes to wiring. Things need to be threaded, crimped and heated in a certain sequence. We slowed down a bit and started again on our simple ground strap, which was turning out to be not as simple as we originally thought.

We cut off the eyelets from the first attempt at the ground strap to get the length correct. Then we used wire cutters to remove the yellow plastic covering from the crimp fit eyelets, because the plastic is unnecessary when we use the shrink wrap.

Once you have everything ready to go, here is the correct order of operations:

  1. Cut the wire to the correct length.
  2. Strip the wire ends.
  3. Push the wire through the sheath.
  4. Thread the wire/sheath combination through a piece of heat shrink wrap.
  5. Crimp the eyelet onto the wire ends.
  6. Use torch to melt the heat shrink wrap into place.
As we move through our correct order of operations, you can see here we have stripped the wire, threaded the wire through the protective sheath and then threaded all of that through a piece of heat shrink wrap. Slow down and think about what you are doing here.

Once all of the correct pieces are threaded through in the correct order, we can finalize this part of the project by crimping the eyelet onto the wire and using our heat shrink wrap.

Here we are ready to crimp our eyelet onto our wire. It is important that the size of the eyelet and the gauge of the wire are compatible for a solid and long-lasting crimp and connection. Some suggest using a small dab of solder here. I can’t argue that.

Using a lighter, a heat gun, or a small torch will easily shrink the heat-shrink wrap into place. The trick here is not to burn yourself and to ensure the heat shrink wrap is in the exact position you want it before you start heating it. Because, once it starts to melt, then that is where is will land, period.

The final product came out looking legit. It has a very professional, clean, look that should last through rough race conditions.

There is a slight learning curve with the torch. Heat is great for shrinking the heat shrink wrap just right, but too much fire can melt things. You have to find that sweet spot when heating things up. I don’t need to admit how many times I had to re-wrap this piece of wire because I was too aggressive with the torch. All that needs to be said is I finally figured it out … eventually.

Small torches are handy for heating shrink wrap. Heat guns also work well too and aren’t as likely to melt things you don’t want melted. My final vote is to use a heat gun instead of a torch.

After a few tries, we finally nailed it. The ground strap came out looking like we wanted it to. It did two things, 1) it replaced a piece of wire that was due to fail and 2) it made the engine compartment look more refined and professional.

The final product came out pretty good. For those of you staring at the header wrap instead of the wiring wrap, that Toolshed Engineer how-to on headers was published in the September 2018 issue of Speed News.

Once we learned the hard way on our “simple and easy” ground strap, we decided to take on some more wiring clean-up projects in the car. There were existing wires that were in the car that we thought could be in harm’s way and didn’t have the professional look we wanted, so it was time to upgrade.

These wires lying on the floor pan in the rear of our Honda Challenge car have been bouncing around in there for a couple of seasons. Our concern was that eventually the vibration would cause the plastic coating on the wires to wear off and cause a short (which is a bad thing). We can fix it!

In attempting to work on the wires in the rear of the car, we realized quickly we needed a different type of wire sheathing. We didn’t want to rewire this part of the car. We simply wanted to add a protective jacketing, which matched what was being supplied by Chandler Autosport. Because these wires were already in place, we couldn’t thread them through the wire sheathing we had purchased online. Back to Amazon, where we found “split” wire sheathing that we could push the wire into from the side. With Prime shipping, we were back in business a day later.

Getting the wires to go into the split sheathing isn’t easy to do. The pro tip is to purchase this handy sheathing tool that guides the wire into the split sheathing with ease. It will cost you only a few dollars and save you hours of frustration.

Once we “harnessed” the skills to build our own ground wires, and sheath existing wires, we stepped up our game and began using water proof pin style electrical connectors to upgrade our wiring harnesses’ connections. We built our own chassis harness to run things like Cool Suits and other accessories in the car, and ensured the wiring in our interior looked professional and would work under harsh racing conditions.

We took our wiring skills up to the next level using the order of operations as described above to create a chassis harness in the rear of the car that could power a removable Cool Suit box, ground the harness to the chassis, and continue to the rear of the car to power the brake lights. The final product looks clean and professional.

If your racecar wiring looks like spaghetti that is about to catch fire, then it is probably time to spend a little money and effort to clean things up. In the end, you will have a more professional looking racecar that won’t let you down when it matters. Happy wiring!

Rob Krider is a NASA National Champion and author of the novel “Cadet Blues,” to read more, or to contact him, go to

Image courtesy of Rob Krider

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