Trailer Brakes Cut Out After a Short Period of Use on a 2002 GMC Sierra 1500

Question:

Im towing a 29 bumper pull with a 2002 GMC Sierra 1500 using a Hayes brake controller. Controller has worked fine for several years but has started working intermittently of late. When I apply the brakes manually they work for a short period of time and then cut out as if there was a circuit breaker opening up. Problem is I dont see where there is a circuit breaker in the wiring system, only a fuse. I am using the factory wiring package. Suggestions?

asked by: Matthew M

Expert Reply:

I would start by using a circuit tester, item # PTW2993 if needed, to test the black wire going into the brake controller. Since the problem will occur with the manual slide activated do this with the circuit tester attached to the power wire. If the power wire shuts off when the brakes cut out, then you know that there is something wrong on the power wire and not inside the brake controller. I do not think this will be the case since the power wire on the 2002 GMC is fused and does not run through a circuit breaker. If it is the case, you may have a relay in the fuse panel under the hood that is not functioning properly.

Most likely you will find that the power wire is okay, and you will need to then test the output wire that runs to the trailer connector and trailer brakes. Use the same procedure as before and if the power drops off of the output wire on the brake controller there is a problem internally with the brake controller. Brake controllers have no user serviceable parts so you will need to replace the brake controller in this situation.

If you decide the controller needs to be replaced, I recommend the Tekonsha P2 # 90885 and the correct wiring adapter that you would need for your Sierra is the # 3025-P. This adapter will make the installation a direct plug-in application.

expert reply by: Robert G