Troubleshooting Brake Controller that Only Works with Manual Override Lever

Question:

I have 2003 ford expedition and when I press the brakes nothing happens but when I manually slide brake button brakes engage

asked by: Rob

Expert Reply:

This is a fairly common problem and the solution is the red wire of the brake controller.

Make sure it is connected to a circuit that only sees voltage when the brakes are applied and none when released. Most likely the connection is the issue and just reconnecting the circuit will cause the controller to work again.

You can also check to make sure that the third brake light fuse is in good condition under the hood of the vehicle as well.

expert reply by: Jameson C