My used GMC came with a wiring harness that had been used with a brake contoller but someone cut the wires a little short when they removed the controller.
The original harness had 6 wires so I ordered a new one with a new brake controller. The harness I received has only 4 wires. I have the diagram for 6 to 4 and it says not to match colors. Now with this new harness that is red, black, white and dark blue do I match wires to the brake controller? I can't find anything that tells me. I've looked this harness up and it's the right one but not exactly like the original harness from the manufacturer. What do I do?
Posted 2007-02-21 1:35 PM (#55992 - in reply to #55987) Subject: RE: Brake control wiring - 2004 GMC
Member
Posts: 43 Location: Cheyenne,Wy
You can match color to color . It is on oem harnesses yopu cant wire color to color on. The red wire is for the brake signal . The black wire is the 12 v power wire. The white wire is the ground and the blue is the brake feed wire.
Posted 2007-03-27 12:10 PM (#57889 - in reply to #56064) Subject: RE: Brake control wiring - 2004 GMC
Veteran
Posts: 150 Location: Le Claire IA
I have a problem with something not working properly.
The wiring of the controller was pretty easy, I used the butt connectors as it said to do though I went thru a good number since the larger didn't crimp that great for me.
I can plug in and the light turns green. I drove the truck and trailer and for some reason I caught that the light got greener as I gave the truck gas??????? It flickered a few times when I applied the brake, let off the brake. Is it the brake switch, the controller wiring which is crimped and covered with tape so it doesn't come apart or a short in the trailer? Does this sound familiar? Can someone point me in a direction...part of me wants to do this on my own and the other part says I'm horse poor to take it in and have someone rewire.
Thank you.
Brake control wiring - 2004 GMC
My used GMC came with a wiring harness that had been used with a brake contoller but someone cut the wires a little short when they removed the controller.
