Why Would Brake Controller Only Work with Manual Override Lever and Not Brake Pedal

Question:

Trailer Brakes work manually but not with pedal. It is a brake force control and a 2022 f350 diesel

asked by: Manuel S

Expert Reply:

This problem is going to be one of two problems. Either the third brake light fuse of the vehicle is blown or the red wire of the brake controller isn't connected properly to a circuit that sees 12 volts when the brakes are applied.

Basically your controller isn't getting the signal it needs to tell it the brakes of the tow vehicle are on and it should start applying the trailer brakes and this is the red wire of the controller.

If it's a proportional controller you should note that it needs to be moving for it to sense an inertia change and apply brake voltage.

expert reply by: Jameson C