1999 GMC Yukon Owner's Manual - Page 246

yellowblue 2. 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 (N) before setting the parking brake. If you have a four-wheel-drive vehicle, be sure the transfer case is not in NEUTRAL (N). 3. Turn off the ignition on both vehicles. Unplug unnecessary accessories plugged into the cigarette lighter or accessory power outlets. Turn off all lamps that aren't needed as well as radios. This will avoid sparks and help save both batteries. And it could save your radio! NOTICE: If you leave your radio on, it could be badly damaged. The repairs wouldn't be covered by your warranty. 4. Open the hoods and locate the batteries. Find the positive (+) and negative (-) terminals on each battery. CAUTION: If your vehicle has air conditioning, the auxiliary electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan. 5-4