Troubleshooting Trailer Brakes that are Always Engaged

Updated 05/15/2018 | Published 05/12/2018

Question:

What would cause the trailer brake magnets to stay magnetized without pushing brake pedal? We first thought it to be my truck however we used another truck to see and it was the same thing.

asked by: Denese S

Helpful Expert Reply:

First of all did this problem just start happening? If the trailer has always worked fine before on the same truck then it's likely a short on the trailer's brake wiring. I would start by cleaning the connector and make sure it's free of any debris or corrosion. Also make sure the breakaway pin is inserted properly. However, it the probem is from the breakaway switch the brakes will only be locked until the breakaway battery dies. If both of these are fine then you need to inspect the wiring on the brake circuit for any damaged, exposed, or pinched wires.

On the other hand, if this is a new to you trailer it could be that the trailer is wired differently than the trucks you tested it with. You can use a 12 volt battery and connect the trailer's ground wire to the negative side and then connect each other wire to the positive side one by one to test their functions. The brake circuit should be in the 7:00 position on the trailer's connector. If this turns out to be the issue it's easiest to just change the trailer's wiring using a junction box like part # 38656.

expert reply by: Charles S