Only One Side of Trailer Brakes Lock Up

Question:

I am troubleshooting a trailer brake problem. When I apply the brake controller manually, one wheel locks up, but the other does not. I plan to check the shoe adjustment on that wheel. I noticed that both magnets emit a high-pitched whine when energized. Is this sound normal or could it indicate a problem with the magnets? Thank you,

asked by: Jim E

Expert Reply:

The high-pitched whining noise you are describing is completely normal for electric trailer brake assemblies. If only one side of the trailer brakes lock up then most likely you just need to adjust the tension on the shoes like you mentioned. If you want to get more technical then you can test for power on the wire leading into the magnet. If you don't get close to 12 volts with the manual override applied and controller at max settings then you have a wiring problem but if you are getting close to 12 volts in the above conditions then the magnet could be bad.

expert reply by: Conner L