1998 GMC Suburban Owner's Manual - Page 151

Ai R BAG This light will come on when you start your engine, and it will flash for a few seconds. Then the light should go out. This means the system is ready. Charging System Warning Light The charging system warning light should come on briefly when you turn on the ignition, before starting the engine, as a check to show you it is working. /tl If the air bag readiness light stays on after you start the engine or comes on when you are driving, your air bag system may not work properly. Have your vehicle serviced right away. The air bag readiness light should tlash for a few seconds when you turn the ignition key to RUN. If the light doesn't come on then, have it fixed so it will be ready to warn you if there is a problem. 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. I t coulcl 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 the air conditioner. 2-73