Tekonsha P3 Trouble Shooting for 2008 GMC Sierra

Question:

I had the Tekonsha P3 brake controller originally installed in a 2007 gmc sierra 3500 and then transferred the unit to a 2008 gmc sierra 2500. the brake controller is now showing and pushing power to trailer brakes when the brake pedal is not pushed in. this happens when the truck is turned on only. when off, the brake controller shows zero. have followed the wiring suggestions of the following: Brake controller red to truck green/white, brake controller black to truck red/black, brake controller blue to truck controller blue, brake controller white to truck white. Not sure how to proceed. Need a brake controller as this truck is hooked up to a 14000# gvw dump trailer for landscaping purposes. Is it time for new brake controlled? Thanks for the help

asked by: Charlie S

Expert Reply:

I reviewed installation instructions, and image you provided, yes it does show that you have the controller wired correctly. It is possibly time for a new controller but I suggest you first attempt to recover functionality of this unit. Clean contacts thoroughly on both the vehicle and trailers 7 ways. Try to reset the unit by breaking power, cause an open circuit to the black wire for at least 15 minutes. You do not want the unit to go into sleep mode, you want it completely off, disconnected from power. You can also try cutting the blue wire about a foot back from the controller and check for power with a circuit tester while using the manual override lever, if power is not being fed back you will probably need to replace, do this after having reset if the reset does not resolve issue.

To replace with what you have, the Tekonsha Prodigy P3 Trailer Brake Controller - Proportional, # 90195.

expert reply by: Michael R