Motorsport Wiring Looms

As OnPoint has grown over the last few years, the website has started to lag behind. One of the areas that we have really grown in is in motorsport electronic systems design and fabrication. We’ve designed and built harnesses for racing teams that compete in many different professional championships, such as SCCA World Challenge, IMSA Continental Tire Sports Car Challenge, IMSA GT3 Cup (Canada and USA), as well as harnesses for Canadian racers who compete in series ranging from local Time Attack all the way up to Canadian Touring Car.

Service Options:

We offer multiple services to cater to just about any budget. We can offer a full hands-off approach, where we tell you what you’ll need, design the harness, come out and measure, complete drawings and fabricate the harness. We can also simply provide a design and drawings for you to take to build your own harness.

There are many online courses now that teach how to successfully complete a harness, and this is a very viable option for someone that is willing to put in the time and wants to save some money. It is worth pointing out however that you first must be very competent with electronics before attempting to build your own harness, or else headaches are certain.

We offer services for chassis harnesses (including switch panels or PDMs), data harnesses, and ECU / engine looms.


Most enduring reliability issues with racecars tend to have something to do with the electrical system. Having a professional design and build the electrical system in your racecar ensures you’ll have a strong foundation for development. There’s nothing worse than watching people waste years trying to sort through electrical gremlins while they should be enjoying their car, or developing it to go faster. While it is a greater up-front cost compared to splicing together an OEM harness, the rewards significantly outweigh the costs. Here’s a list of my favorite advantages of a motorsport loom:

  • Reliable. This is clearly #1. With proper electronic documentation, you’ll know exactly what each wire does in each part of the harness, and be able to check it at any time directly from your phone or computer. There are no loose wires, unknown splices, and guesses. Everything is designed and built specifically for your car, with your electronics/ecu/data system. Our harnesses are covered in chemical and abrasion resistant heatshrink and capable of taking far more abuse than any OEM harness out there.
  • Lightweight. OEM wiring in a converted racecar can be upwards of 45lbs. Throw out every bit of wire in your car and start from scratch. Our customers CONSTANTLY tell us they wish they’d done it earlier.
  • Good looking. Nothing ruins the interior and engine bay of a racecar like OEM wiring and decades old electrical tape. Fuse boxes dangling and cut wires are gross. Don’t be that guy.
  • Expandable. Our harnesses are built with the future in mind. You’ll have spare connectors for future functions, spare connectors for sensors and other data add-ons that you may want to install down the road.
  • Integrated. Don’t have bundles of harness on top of harness, different types of sensor cables, ECU harnesses and power lines running on top of each other. Everything is integrated neatly and in an organized fashion.
  • Replaceable. Should your harness be damaged down the road, know that our documentation and serial numbering allows us to re-build any harness without ever needing to see the car again.


Below you’ll find some example drawings and photos of our harnesses. We use Deutsch Autosport connectors when requested, and we can also use cheaper interconnection options for those on a less professional budget.