Trailer Wiring Harness

Basic Trailer Wiring

The trailer wiring harness, with a seven-pin connector, is located at the rear of the vehicle and is tied to the vehicle's frame. The harness connector can be plugged into a seven-pin universal heavy-duty trailer connector available through your dealer.

The seven-wire harness contains the following trailer circuits:
• Yellow: Left Stop/Turn Signal
• Dark Green: Right Stop/Turn Signal
• Brown: Taillamps
• Black: Ground
• Light Green: Back-up Lamps
• Red/Black: Battery Feed
• Dark Blue: Trailer Brake*

*The fuse for this circuit is installed in the underhood electrical center, but the wires are not connected.

They should be connected by your dealer or a qualified service center.

If the back-up lamp circuit is not functional, contact your dealer.

If a remote (non-vehicle) battery is being charged, press the Tow/Haul mode switch located on the center console near the climate controls.

This will boost the vehicle system voltage and properly charge the battery. If the trailer is too light for Tow/Haul mode, turn on the headlamps (non-HID only) as a second way to boost the vehicle system and charge the battery.

    See also:

    Hands-Free Calling
    1. Push . System responds: “OnStar ready.” 2. Say “Dial.” System responds: “Please say the name or number to call.” 3. Say the entire number without pausing, including a “1” and the ...

    Cruise Control
    Cruise Control : Press to turn cruise control on and off. The indicator comes on when cruise control is on. + RES: Press briefly to make the vehicle resume to a previously set speed, or press and ...

    Storing Memory Positions
    To save into memory: 1. Adjust the driver seat and seatback recliner, both outside mirrors, and the throttle and brake pedals, if equipped. See Power Mirrors on page 2‑15 and Adjustable Thrott ...