Troubleshooting Trailer Brake Controller Working with Manual Slide But Not With Brake Pedal

Question:

I have power to the brake controller. When I push the manual slide I have power to the blue wire but when I push down on the brake pedal I dont have power. Does this mean I have a bad brake controller?

asked by: Jim K

Expert Reply:

There are a few more things I need you to check before we know the brake controller is faulty. First you will need to test the wire(typically red) coming from the brake switch for power. A Test Light # PTW2993 will allow you to test this wire to ensure you are getting power from the brake switch when you press the brake pedal. If you do not have power you may have a bad fuse or switch. Be sure to check your owners manual for any fuses/relay.

Next we need to know exactly what brake controller you have. If you are using a proportional controller and performing the test while parked you will not see any power sent to the trailer brakes through the blue wire. This is due to the controller not sensing the inertia of the vehicle stopping and not allowing power. Knowing which brake controller you are using will also allow us to check and see if your controller is required to be mounted within a certain angle range. If set outside the angle range it will not work properly.

Let me know what you find with the test above and what controller you have so I can help to verify the controller is bad.

expert reply by: Bud M