Electric Trailer Brakes Lock Up Even with No Power Getting to Them

Published 09/25/2015

Question:

I have a single axle trailer with brakes that we generally do not have wired up to anything. Recently the brakes started to lock up. We disconnected the wiring harness and they unlocked briefly but they locked up again. With no power to them. We ended up cutting the wires to the brake drum and they are still locked. What would cause this as there is no power.

asked by: Barry G

Expert Reply:

Your trailer might be possessed! If the trailer has a battery on it with a breakaway system then that is likely where the power was coming from. Even if there wasn't a breakaway system, if there is a battery on the trailer then it is possible that corrosion on or in the trailer connector could be causing a short from the 12 volt circuit to the brake circuit.

Cutting the power to the magnets should cause the brakes to release. But in this case that didn't work. Since you mentioned that you usually don't use the brakes I theorize that some corrosion or road gunk has caused the brakes to get stuck in the position they are in. Once you physically and manually release them the problem should not happen again with no power wires going to the magnets.

If you want to replace the brakes I have included a link to the electric brakes that we carry.

expert reply by: Michael H