Troubleshooting a Brake Controller that Sometimes Activates with Brakes but Sometimes Only Shows .C

Question:

I have one of your units mounted in my work truck and sometimes when the brakes are applied the led read out will show how many the volts and then the letter C will stay on and when you reapply the brakes it stays on and does not do a read out

asked by: Harry H

Expert Reply:

It sounds like the problem is on the brake switch circuit run to the Prodigy P2 brake controller. I would check the red wire of the brake controller and make sure that it is securely attached to a circuit that only sees voltage when the brakes are applied.

What I think is happening is that when you sometimes apply the brakes your brake controller is getting voltage on the red wire and it is activating and a voltage number will appear on the controller, and then sometimes when you apply the brakes the red wire is not making a good enough connection for the controller to register that you applied the brakes so it does not turn on and instead just shows the .c, which means it senses a trailer but that it is not activating your trailer brakes.

I attached an FAQ article on troubleshooting brake controller installations for you to check out also.

expert reply by: Jameson C