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:
Hazard Warning Flashers
(Hazard Warning Flashers):
Press this button located on top of the steering column, to make the front and rear turn signal lamps flash on and off. This warns others that you are having trouble. Pr ...
Tire Pressure Monitor Operation
This vehicle may have a Tire Pressure Monitor System (TPMS).
The TPMS is designed to warn the driver when a low tire pressure condition exists. TPMS sensors are mounted onto each tire and wheel assem ...
Potential Issues
Some OnStar services are disabled after five days. OnStar cannot perform Remote
Door Unlock or Stolen Vehicle Assistance after the vehicle has been off continuously
for five days. After five days, ...





