Brake Controller Not Functioning Properly On a 2004 Chevrolet Pickup When Brake Pedal is Pressed

Expert Reply:

It sounds as if you may have the incorrect brake controller wiring harness. The correct wiring harness for the 2004 Silverado 2500 HD is the Universal Brake Control Wiring Adapter 2003 - 06 Chevrolet, GMC, Cadillac, item # 20264. Unplug the harness and check the wire locations in the connector.

When holding the connector with the locking tab in the down position the red wire should be in the bottom right position closest to the locking tab. If the red wire is in the top left position, farthest from the locking tab then it will need to be moved.

To get the red wire out you will need to remove the blue locking clip and press on a very small locking tab on the connection side of the terminal. This is the only change that will need to be made. Remember to reinstall the blue locking clip.

When the connector is wired properly the brake controller will be activated when the brake pedal is pressed.

expert reply by: Bob G