Troubleshooting Trailer Brake Output Circuit Melting Wire After Bearing Change

Published 10/08/2015

Question:

I have a bri-mar dump trailer that has an electric braking system on it as i was doing my pre tow testing the other day I pulled the pin for the breakaway switch to test it and the wires going to it started smoking and melted the insulation off from them. The wires that melted were the 12v + from the battery and the feed line to the brakes. I am trying to understand why this would happen. the only difference between the last use and now is new wheel bearings. I am not sure weather one of the magnets in the wheels has shorted out causing a short, if some kind of moisture got into the breakaway switch causing an issue, or if there is a bad ground in the system that could be at fault. just looking for places to start looking for issues and wondering if there is any way to test the magnets to see if there is an issue with them?

asked by: Mike S

Helpful Expert Reply:

There was definitely a short somewhere on your brake output circuit. A bad ground would just cause the circuit to not function. I attached a help article that covers everything on testing brake magnets.

It is possible that when you were replacing the bearings you damaged the brake output circuit and that is why it is shorting out.

expert reply by: Jameson C