Trouble Shooting Inoperable Electric Brakes on a 10K Trailer

Expert Reply:

Since you have fresh parts in the hubs and provided they are installed properly, I suspect there is a problem somewhere in the wiring or with the brake controller installation and set up. You will need to check the whole system, step by step, to find out where the problem is. If you have used your truck successfully with other trailer brake equipped trailers, then the brake controller and vehicle wiring should be fine and you can skip the first 2 steps. If you tried it on different vehicles that have a properly working system, and the trailer brakes still did not work, then the problem is probably in the trailer wiring so you can skip the second step below.

Step 1 - First you need to check the brake controller, make sure all the connections are made where they should be and that they are working properly. I have included a link to a page about installing a brake controller from scratch. Some of it may not be relevant if you have a factory tow package on your vehicle with the 7-Way connector. Use the wiring diagram at the bottom of the page to check your brake controller connections. Additionally I have included a video on testing the wiring on a brake controller if it is already hooked up. The tester shown in the video is part # 40376.

Step 2 - If everything is working right with the brake controller, the problem could be in the wiring going back to the 6 or 7-way connector where the trailer plugs in to. You can use the circuit tester above or we have plug-in testers that plug into your 6 or 7-way connector on your vehicle to show which circuits are functioning. Part # TR20116 for a 6-way, part # TR20117 for a 7-way.

Step 3 - Finally, it may be a problem with the trailer wiring. Check all the wires for the trailer with a circuit tester. If you are unsure if the brakes are wired properly, pull those apart too and make sure you have one wire from the magnet grounded and the other wired to the brake controller wire. Please note that you want the ground as close as possible to the trailer brakes. If you have run the ground all the way up to the harness, then that may be your problem.

If you have done all this and the brakes still do not function, it may be a problem with the setup of the brake controller. If you write back with the make and model of your brake controller, I will be able to help you figure out if it was not set up properly. This is more of a problem for proportional controllers, but can also be a problem for time delayed units.

expert reply by: Patrick B