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:
Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and
GPS signal reception. Cellular reception is required for OnStar to send remote signals
to the vehicle. ...
Fluids
Proper fluid levels and approved fluids protect the vehicle’s systems and components. See Recommended Fluids and Lubricants on page 11‑12 for GM approved fluids.
• Engine oil and windshield ...
Finish Damage
Quickly repair minor chips and scratches with touch-up materials available from your dealer to avoid corrosion. Larger areas of finish damage can be corrected in your dealer's body and paint shop. ...





