GMC 2005 Sierra 1500 Pickup Owner's Manual page 388

Camper/Fifth-Wheel Trailer Wiring Package
The eight-wire camper harness is located under the
front edge of the pickup box on the driver's side of the
vehicle, attached to the frame bracket. A connector
will have to be added to the wiring harness which
connects to the camper.
The eight-wire harness contains the following
camper/trailer circuits:
•
Yellow: Left Stop/Turn Signal
•
Dark Green: Right Stop/Turn Signal
•
Brown: Taillamps
•
White: Ground
•
Light Green: Back-up Lamps
•
Light Blue: Center High-Mounted Stoplamp
(CHMSL)
•
Red: Battery Feed
•
Dark Blue: Trailer Brake
4-94
If your vehicle is equipped with the "Heavy-Duty
Trailering" option, please refer to "Heavy-Duty Trailer
Wiring Package" earlier in this section.
When the camper-wiring harness is ordered without the
heavy-duty trailering package, an eight-wire harness
with a seven-pin connector and separate CHMSL
connector are located at the rear of the vehicle and are
tied to the vehicle's frame.