Troubleshooting Prodigy P3 Trailer Brake Controller That Powers Brakes When Motionless

Question:

I have the tekonsha brake controller, p3 I believe. It frequently will stay on after a stop and will also occasionally activate on hills, up or down. It will turn off if I tap the brake pedal. Any ideas?

asked by: Sean

Expert Reply:

If your Tekonsha Prodigy P3 brake controller # 90195 continues to apply the trailer brakes after you have come to a full stop then most likely either the unit is damaged internally or the red wire that delivers the triggering "brakes are being applied" signal to the controller is connected to the wrong circuit on the vehicle.

If you have a circuit tester like # PTW2992 you can test the blue output wire at the back of the controller. Sever the BLUE wire a few inches from the controller (leaving enough to re-attach it). While sitting still apply the tester to this wire. If you detect a brake output signal on the blue wire while you are motionless then the unit is damaged. If you are sitting still the P3 should generate output only when the manual override lever is pressed.

The fact that tapping the brake pedal causes the brakes to release also tends to suggest an internal fault in the controller.

expert reply by: Adam R