1998 GMC Safari Owner's Manual - Page 221

If you do not have the optional trailering package, your vehicle will still have a trailering harness.The harness is If you have the optional trailering package, your vehicle located near the passenger's rear wheel well. It side will have an eight-wire harness, including the center consists of six wires that may be used by after-market high-mounted stoplamp battery feed wire. The harness trailer hitch installers. The technician can use the is stored on the passenger's of the vehicle near the side following colorcode chart when connecting the wiring rear wheel well. This harness has 30 amp battery feed a harness to your trailer. wire and no connector, and should be wired a by 0 Brown: Rear lamps. qualified electrical technician. After choosing an aftermarket trailer mating connector pair, have the 0 Yellow: Left stoplamp and turn signal. technician attachone connector to the eight-wire trailer harness and the other connector to the wiring harness on0 Dark Green: Right stoplamp and turn signal. the trailer. Be sure the wiring harness on the trailer is 0 White (Heavy Gage): Ground. taped or strapped to the trailer's frame rail and leave it 0 Light Green: Back-up lamps. loose enough so the wiring doesn't bend or break, but not so loose that it drags on theground. The eight-wire 0 White (Light Gage): Center High-Mounted harness mustbe routed outof your vehicle between the Stoplamp. rear door and the floor, with enough the harnessleft of 0 Blue: Auxiliary circuit (eight-wire harness only). on both sidesso that the trailer the body won't pull it. or 0 Orange: Fused auxiliary (eight-wire harness only). Store the harnessin its original place. Wrap the harness together and tie it neatly so it won't be damaged. Trailer Wiring Harness 4-37