2003 GMC Sierra 1500 Pickup Owner's Manual - Page 371

The eight-wire harness contains the following trailer circuits: Yellow:LeftStop/TurnSignal Dark Green:Right Stopnurn Signal 0 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 Stopnurn Signal Dark Green: Right Stopnurn Signal Brown: Taillamps White: Ground Light Green: Back-up Lamps Light Blue: Center High-Mounted Stoplamp (CHMSL) Red: Battery Feed Dark Blue: Trailer Brake Brown: Taillamps White: Ground LightGreen:Back-up Light Blue: CHMSL Red:Battery Feed DarkBlue:TrailerBrake Lamps 4 0 0 0 If your trailer is equipped with electric brakes, you can get a jumper harness (electric trailer brake control) with a trailer battery feed fuse from your dealer. If you need to tow a light-duty trailer with a standard four-way round pin connector you can also get an adapter from your dealer. A jumper harness for an electric trailer brake controller and a trailer battery feed fuse are included with this trailering package. (See lnstrument Panel Jumper Wiring Harness later in this section.) 4-90