Finding Power Wire for Third Brake Light in 2011 GMC Sierra 1500

Published 04/12/2019

Question:

Hi, Im unable to locate the light blue wire needed to power the brake light. I have a 2011 GMC 1500/w trailer pkg I thought it would be somewhere in the 7 way harness. Is it further back, or coming from another location? Thanks

asked by: James G

Expert Reply:

There is a dedicated brake light only wire located up under the dash and to the left of the steering column. It is with a wire bundle held together with a white tag. There should be an orange wire that is the center high mount stop lamp wire (CHMSL) that you could use.

You would need to attach wire to the end of it, route it through the firewall, under the truck, and over to where it needs to go.

It is also possible that the truck has a wire under the bed somewhere for this purpose. A place that sells and installs camper shells might be able to tell you where the wire might be.

expert reply by: Jameson C