Troubleshooting P3 Brake Controller for No Ouput with Manual Override

Question:

On my Tekonsha P3 brake assist in the troubleshooting menu I have good voltage on vehicle battery, stop light and output voltage, but not getting voltage to vehicle plug and showing output current at 0.35a with the manual brake lever activated. these tests have been done with the vehicle stationary

asked by: Darin J

Expert Reply:

If your P3 Brake Controller part # 90195 is installed correctly and no brake output voltage is on the blue wire then it sounds like the controller is bad and needs to be replaced. I would have you test the red wire of the controller to test for voltage when the brakes are applied but the controller already told you this in the troubleshooting menu.

You could try cutting the blue wire about 6 inches back from the brake controller or before the connection point with the brake output wire and use a circuit tester like part # PTW2993 and test the blue wire on the brake controller for power when you activate the manual override. If voltage was here then the problem is a short on the brake output circuit somewhere between the controller and trailer connector. Most likely corrosion on the 7-way would cause this. Check the back and front for corrosion or anything else like cut or exposed wire.

expert reply by: Jameson C