Tekonsha P2 Brake Controller Shows Power without Stepping on the Brake Pedal on 2002 Toyota 4Runner

Question:

Finished up installation, and the brake controller shows volts on controller with no brakes being pushed, only way the volts go away is to turn the controller all the way down. When I hook up to a trailer and try to turn up controller with vehicle in park with no brakes being pushed it still shows the volts at all times. What could be the problem?

asked by: Jason C

Expert Reply:

There could be a short to the blue wire or you could also have the red wire attached to the wrong circuit. First check the red wire with a circuit tester like # PTW2993 if needed. If it is showing power without pressing the pedal, then you know it is connected to the wrong brake switch wire.

Use the tester to test the wires on the brake switch. You want the one that only shows power when you step on the brake pedal. If the wire you find also shows power with the head lights or turn signals on it is not the correct wire.

You will also want to make sure that the controller is not tilted or turned to the side. It has to be straight. If it is tilted that can throw of the internal sensors and it will not work properly resulting in to little or too much braking.

Sometimes a dirty or corroded trailer connector on a vehicle and/or trailer can cause a short and cause power to draw on the brake output circuit. Clean out any dirt and corrosion. Corrosion can also build up where the wires attach to the connector. I have also included a link to an FAQ article on troubleshooting brake controller installations that should help.

expert reply by: Michael H