Troubleshooting Trailer Brakes That No Longer Work

Updated 05/08/2018 | Published 05/06/2018

Question:

The trailer brakes were locking up with very little pressure on the brake pedal. Now I have no trailer brakes. I have manually adjusted them and the controller seems to be working fine. The brakes still arent working.

asked by: Phil

Expert Reply:

If your trailer brakes have stopped working there are a number of potential issues, starting with a potentially bad ground on your connectors or brake magnets. Additionally, corrosion or dirt may be the cause of a short in a trailer connector. Check the plug to see if there is any type of corrosion built up that may be hampering it's functionality.

You will also want to test the brake output pin on the 7-way socket; it should only show power with the manual override. If it shows power any other time then there is a short somewhere between the connector and the brake controller you will need to find.

If the truck side checks out then it could be the wiring to the brake magnets or possibly the magnets themselves. Inspect the power wires to the magnets and look for wires that may be pinched or otherwise damaged and fix as necessary.

You'll want to visually inspect the magnets; if you can see the copper windings coming through the magnets will need to be replaced. To test the magnets you can follow the help article I have linked. I have also attached some help articles on testing and troubleshooting brake controllers for you to check out.

expert reply by: Kyle S