1996 GMC Jimmy Owner's Manual - Page 209

Maintenance When Trailer Towing Your vehicle will need service more often when you're pulling a trailer. See the Maintenance Schedule for more on this. Things that are especially important in trailer operation are automatic transmission fluid (don't overfill), engine oil, axle lubricant, belt, cooling system and brake adjustment. Each of these is covered in this manual, and the Index will help you find them quickly. If you're trailering, it's a good idea to review these sections before you start your trip. Check periodically to see that all hitch nuts and bolts are tight. 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. 0 DARK BLUE: Use for electric trailer brakes or auxiliary wiring. RED: Use for battery charging; it connects to the starter solenoid (eight-wire harness only). LIGHT GREEN: Back-up lamps (eight-wire harness only). BROWN: Taillamps and parking lamps. YELLOW: Left stoplamp and turn signal. DARK GREEN: Right stoplamp and turn signal. WHITE (Heavy Gage):Ground wire. WHITE (Light Gage): Auxiliary stoplamp. 0 0 0 0 0 0 0 Trailer Wiring Harness The light duty trailer wiring is a six-wire harness assembly. The heavy duty trailer wiring is an eight-wire harness assembly. The harnesses arestored under the vehicle, along the passenger-side frame crossmember on two-door vehicles or on the driver's side corner frame 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. 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. 4-56