Finding the Brake Light Signal to Install a Brake Controller on a 2014 GMC Terrain

Updated 01/19/2015 | Published 01/18/2015

Question:

Can I just get a signal from any tow vehicle brake light to send to the trailer brake controller? I want a trailer controller like 5504 but cant find a brake signal under the dash.

asked by: Mark

Expert Reply:

The GMC Terrain is the GMC equivalent of the Chevy Equinox. The Equinox has a known issue regarding the brake switch input that you are describing. Basically, it is not present at the brake switch wiring. You will have to get the signal from the body control module (BCM).

I have included a picture that should help. However, you will want to check with a GM tech to make sure the correct signal is in the same place on the 2014 models.

The purpose of the brake signal is to tell the controller you are stepping on the brake so you couldn't get the signal from a different source unless it was a dedicated brake light only.

expert reply by: Michael H