1998 GMC Savana Van Owner's Manual - Page 201

Trailer Wiring Harness The light-duty trailer wiring harness is a six-wire harness assembly. The optionalheavy-duty trailer wiring package is an eight-wire harnessassembly. The harness is stored under the vehicle, along thedriver's side rear corner of the framerail. The heavy-dutytrailer wiring harness has a 30-amp feedwire. Both harnesses come without connectors and should be wired by a qualified electrical technician. The techniciancan use the following color code chart connecting the when wiring harness to your trailer. 0 Light Green: Back-up lamps 0 0 Brown: Parking lamps Yellow: Left stoplamp and turn signal Dark Green: Right stoplamp and turn signal White (heavy gage): Ground wire White (light gage): Center high-mounted stoplamp 0 0 0 Dark Blue: Use for electric trailer brakes (eight-wire harness only) Orange: Trailer accessory (eight-wire harness only) 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 hamess in its original place. Wrap the harness together and tie it neatly so it won't be damaged. 4-37