No Power to Brake Controller 90885 When the Brake Pedal is Applied on 2005 GMC Sierra

Question:

I am not getting power back to the brake controller when the brake pedal is applied in my 05 seiarra 2500 HD pick up. Any help would be great. Thx

asked by: Wayne

Expert Reply:

First I suggest you open your fuse box and check the fuse for the center high-mount stop light (CHMSL). If this fuse is blown it could account for the problem. If the fuse is not blown you can next check the wiring of the connector on the vehicle side of the brake controller harness.

For your model year the red wire should be connected to pin D on the wiring adapter for the brake controller. Please refer to the attached photo. The red wire carries the signal from the stop lamp switch to the brake controller when the brake pedal is pressed. This wire may be connected to another pin (pin A) and will need to be moved to the slot for pin D. If you prefer not to re-wire this connector you can instead use part # 3015-P, which is a custom brake control harness specific to your vehicle.

You also need to make sure you are plugged into the correct port on the connector block under the dash. When you remove the cover you will see several ports, some are occupied, some not. The brake controller needs to be connected to the port 2nd from the left on the top row. Please see photo attached.

I have also linked a brake control installation video and help article specific to your vehicle.

expert reply by: Adam R