Troubleshooting A Tekonsha P3 Brake Controller that Says Power on the Display

Expert Reply:

The Tekonsha P3 Brake Controller, item # 90195, has built in troubleshooting diagnostics that you can access by pressing the menu button then selecting help and pressing ok. You will then be able to monitor the battery voltage supplied to the unit, black wire, the voltage supplied when the brake pedal is pressed, red wire, and the output voltage and amps sent to the trailers brakes,blue wire. If one of these connections is wrong you should get a warning screen.

If you have the caution screen that says power loss on it then this means that the power to the trailer brakes is being interrupted and you will need to check the blue output wire and ground connection for the controller, connector, trailer and trailer brakes.

If you are talking about the display being powered up when the trailer connector is not in use then this is normal and after fifteen minutes of no use the display will go blank when it goes into power saving mode.

expert reply by: Bob G