1999 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 256
1999 Chevrolet Silverado 1500 Pickup Manual
Page 256 highlights
yellowblue Basic Trailer Wiring Package (Diesel Engine) Regular and extended cab pickups equipped with a 6.5L Turbo Diesel engine have an eight-wire trailer towing harness. * The single CHMSL wire is tied to the seven-wire harness and is used if your trailer or cap are equipped with a CHMSL. The eight-wire harness contains the following trailer circuits: D D D D D D D D Yellow: Left Stop/Turn Signal Dark Green: Right Stop/Turn Signal Brown: Taillamps White: Ground Light Green: Back-up Lamps Light Blue: CHMSL Red: Battery Feed Dark Blue: Trailer Brake The trailer wiring harness with a seven-pin connector and separate Center High-Mounted Stoplamp (CHMSL) connector are located at the rear of the vehicle and are tied to the vehicle's frame.* The harness connector can be plugged into a seven-pin universal heavy-duty trailer connector available through your GM dealer. If you need to upgrade your vehicle to heavy-duty trailering, a brake controller harness and a seven-pin universal heavy-duty trailer connector are available from your GM dealer. 4-66