2010 GMC Savana 2500 Cargo Owner's Manual - Page 261

Leaving After Parking on a Hill 1. Apply and hold the brake pedal while you: Trailer Wiring Harness The optional heavy-duty trailer wiring package includes a wiring harness, with a seven-pin connector at the rear of the vehicle and a four-wire harness assembly under the driver side of the instrument panel. The four-wire harness assembly comes without a connector. If the vehicle does not have a trailer hitch, the seven-wire harness assembly with connector is taped together and located in a frame pocket at the driver side rear left corner of the frame. If the vehicle has a trailer hitch, the seven-wire harness assembly with connector is attached to a bracket on the hitch platform. In both cases, the seven-wire harness has a connector and includes a 30-amp feed wire. • start the engine, • shift into a gear, and • release the parking brake. 2. Let up on the brake pedal. 3. Drive slowly until the trailer is clear of the chocks. 4. Stop and have someone pick up and store the chocks. Maintenance When Trailer Towing The vehicle needs service more often when pulling a trailer. See this manual's Maintenance Schedule or Index for more information. Things that are especially important in trailer operation are automatic transmission fluid, engine oil, axle lubricant, belts, cooling system and brake system. It is a good idea to inspect these before and during the trip. Check periodically to see that all hitch nuts and bolts are tight. 5-37