Question Was Asked By - Eric

Brake Controller Wiring Identification on a 2007 GMC Sierra

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Question:

I have a 2007 GMC Sierra 4 door 4x4 truck with a tow package and wish to install a Good brake controller for 2 axles 4 breaks? I have looked through your info and do not seem to match up the wiring with hooking to the truck under the dash? what I have found is..... No molex plug connection? did find 5 wires labeled as... dark blue.....Aux Red/blue stripe......batt lite blue/white stripe/ CHMS orange.....CHMSL White.....GND I have no idea what CHMS is? Nor what CHMSL is? i,m not sure if theese are the wires i,m looking for? but think they could be for a controller? any help would be great.

asked by: Eric

Expert Reply:

The dark blue wire would attach to the blue wire coming off of your brake controller. The white wire would match up with the white wire. I would recommend using a circuit tester, part # 40376, to verify the function of the remaining wires. The light blue (which should show current only when the brake is pressed) would go to the red controller wire, and the red wire (which should show 12v with the ignition on) would attach to the black wire on the controller. The remaining wire is not used, and should show 12v when the headlights are on.

I have added a link to a brake controller FAQ page that lists typical wire colors for brake controllers, but always use a circuit tester to double check.

expert reply by: Mike

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