2003 GMC Sierra 1500 Pickup Owner's Manual - Page 427

2. If you have a vehicle with a diesel engine with two batteries (or more), you should know before you begin that, especially in cold weather, you may not be able to get enough power from a single battery in another vehicle to start your diesel engine. If your vehicle has more than one battery, use the battery that's closer to the starter - this will reduce electrical resistance. 4. Turn off the ignition on both vehicles. Unplug unnecessary accessories plugged into the cigarette lighter or accessory power outlets. Turnoff the radio and all lamps that aren't needed. This will avoid sparks and help save both batteries. And it could save your radio! 5. Open the hoods and locate the positive (+) and negative (-) terminal locations of the other vehicle. Your vehicle has a remote positive (+) jump starting terminal and a remote negative(-) jump starting terminal. You should always use these remote terminals instead of the terminals on the battery. The remote positive (+) terminal is located behind a red plastic cover near the engine accessory drive bracket. To uncover the remote positive (+) terminal, open the red plastic cover. The remote negative (-) terminal is located on the engine drive bracket on all V8 and diesel engines, and on the thermostat housing on the 8.1 L engine. On V8 engines it is marked "GND." 3. Get the vehicles close enough so the jumper cables can reach, but be sure the vehicles aren't touching each other. If they are, it could cause a ground connection you don't want. You wouldn't be able to start your vehicle, and the bad grounding could damage the electrical systems. To avoid the possibility of the vehicles rolling, set the parking brake firmly on both vehicles involved in the jump start procedure. Put an automatic transmission in PARK (P) or a manual transmission in NEUTRAL before setting the parking brake. If you have a four-wheel-drive vehicle, be sure the transfer case is in a drive gear not in NEUTRAL. Notice: If you leave your radio on, it could be badly damaged. The repairs wouldn't be covered by your warranty. On V6 engines the remote negative (-) terminal is located on a tab attached to the engine accessory drive bracket where it is marked "GND." See Engine Compartment Overview on page 5-12 for more information on location. 5-52