Troubleshooting Brake Controller that Only Works with Manual Override Lever

Updated 06/19/2017 | Published 06/17/2017

Question:

When I step on the break the controller does not activate the breaks but I can manually stop the trailer with the manual lever. What am I doing wrong?

asked by: Jon H

Expert Reply:

Sounds like the problem is on the stoplight circuit wire. This wire (red in color) attaches to the stoplight circuit of your tow vehicle and is what tells the controller the brakes are being applied and to start applying the trailer brakes.

Check the condition of the connection of the red wire of your controller. It may not be making a secure connection, or it's not installed on the correct circuit. Use a circuit tester like part # PTW2993 to test to make sure the circuit it is connected to sees voltage when the brakes are applied and none when the brakes are released. Another possibility is a blown third brake light fuse under the hood of the vehicle.

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

expert reply by: Jameson C