Troubleshooting Trailer Brakes that Stopped Working

Question:

I have a trailer with electric brakes and all was fine for a year. Then the electric controller in the cab started acting up and only worked sometimes. Then it stopped all together. The controller is a Reese Pilot and when the trailer is connected it would show a c on the display. It does not show that any longer. I replaced the controller with a new identical controller. Same issue. I checked connectivity and the controller has power and when the brake pedal is depressed it shows power on the electric brake wires all the way to the split at the tandem axels on the trailer. I also sent power through the ground to confirm the ground wires are good and they are also good to the split at the tandem wheels. I know I could have 1 bad electric brake magnet but shouldnt the others still work? I cannot hear any of them engaging anymore when the brake is depressed. Using the manual override on the controller gets the same result. All other trailer lights work fine. Any ideas?

asked by: Doug P

Expert Reply:

It sounds like you have determined exactly where the problem is...the Y where the brake output circuit splits to go to each brake assembly. If the voltage is before that but not after the problem is definitely right there. Inspect where the wires split off and fix any obvious signs of damage.

Have you tried running 12 volts from a jumper wire from a vehicle battery to the assemblies to see if you can get the magnet to activate? If you cut the output wire going to an assembly and then run the jumper wire to it you should hear the magnet click as it sticks to the inside of the drum assembly. This would further prove that the problem is in the wiring.

I attached an FAQ on trailer wiring and brake controllers for you to check out also.

expert reply by: Jameson C