Troubleshooting Recently Replaced Electric Trailer Brake Assemblies That Arent Functioning

Updated 04/08/2021 | Published 04/07/2021

Question:

I have a Trailer that I just replaced the brakes on. My brake controller works because I use it on other trailers, and have no issues. Need some help troubleshooting.

asked by: Ryan

Expert Reply:

Due to the fact that you've tested the vehicle with other trailers, and found that the brakes worked fine, the problem lies in the brake wiring on the trailer.

I'd check the connections at the brake magnets. Each magnet has 2 wires exiting the magnet. One wire connects to the brake output circuit from the brake controller, the other needs a secure, non-corroded or dirty connection to the trailer frame. Check out the output circuit on the trailer, it's usually fed by a blue wire. Make sure there aren't any loose connections or pinched wires. Make sure all wire connections are completely sealed against the elements. Each ground connection for the brake magnets should be tightly made to clean metal on the trailer frame. If the ground points are corroded, even slightly you can refresh them my taking the area around the ground connection down to bare metal. Attach each ground connection to the trailer frame using a self tapping screw driven through a ring terminal connected to the ground wire. If you install a star washer between the ring terminal and the trailer frame, the washer will get a really good bite into the trailer frame for a reliable connection. Once installed, give the connections a quick shot of rust inhibiting spray paint like Rust Oleum to keep the connection free of corrosion.

expert reply by: Mike L