2004 GMC Savana Van Owner's Manual - Page 152

Charging System Light {CAUTION: If the air bag readiness light ever comes on when you have turned off the air bag, it means that something may be wrong with the air bag system. The right front passenger's air bag could inflate even though the switch is off. If this ever happens, don't let anyone whom the national government has identified as a member of a passenger air bag risk group sit in the right front passenger's position (for example, don't secure a rear-facing child restraint in your vehicle) until you have your vehicle serviced. This light should come on briefly when you turn on the ignition, before starting the engine, as a check to show you it is working. After the engine starts, the light should go out. If it stays on or comes on while you are driving, you may have a problem with your charging system. It could indicate a problem with the generator drive belt, or some other charging system problem. Have it checked right away. Driving while this light is on could drain your battery. If you must drive a short distance with this light on, it helps to turn off all your accessories, such as the radio and air conditioner. 3-30