1999 GMC Jimmy Owner's Manual - Page 252

yellowblue Trailer Wiring Harness The light-duty trailer wiring is a six-wire harness assembly. The optional heavy-duty trailer wiring is an eight-wire harness assembly. The harnesses are stored under the vehicle, along the passenger-side frame crossmember on two-door vehicles or on the driver's side corner frame rear crossmember on four-door vehicles. The heavy-duty trailer wiring has a 30-amp feed wire with an inline fuse located by the junction block. See "Fuses and Circuit Breakers" in the Index. Both harnesses have no connector and should be wired by a qualified electrical technician. The technician can use the following color code chart when connecting the wiring harness to your trailer. D Light Green: Back-up lamps (eight-wire harness only). D Brown: Taillamps and parking lamps. D Yellow: Left stoplamp and turn signal. D Dark Green: Right stoplamp and turn signal. D White (Heavy Gauge): Ground wire. D White (Light Gauge): Auxiliary stoplamp. Securely attach the harness to the trailer, then tape or strap it to your vehicle's frame rail. Be sure you leave it loose enough so the wiring doesn't bend or break, but not so loose that it drags on the ground. Store the harness in its original place. Wrap the harness together and tie it neatly so it won't be damaged. D Dark Blue: Use for electric trailer brakes or auxiliary wiring. D Red: Use for battery charging; it connects to the starter solenoid (eight-wire harness only). 4-56