Should a Brake Controller Blue Wire have Voltage All the Time

Published 06/13/2013

Question:

The blue wire at the controller has 12 volts at itwhen not in use does the controller have a problem

asked by: Bernie B

Expert Reply:

The only time there should be power on the blue wire when testing it should be when you are applying the manual override. If it shows power at any other time that indicates a problem inside the controller and it will need to be replaced.

Also make sure that the red wire is only showing power with the brake pedal. If it shows power at any other time like when the head lights or turn signals are on, or just any time when the brake pedal is not pressed then it is connected to the wrong wire on the brake switch and you will need to use the circuit tester on the brake switch wires to find the correct wire.

Our most popular controller is the P2, # 90885. It is easy to set up and use and it is very reliable. I have included a link to an FAQ article covering brake controllers and a link to an FAQ on troubleshooting controllers for you.

expert reply by: Michael H