1996 GMC Safari Owner's Manual - Page 115

Charging System Indicator Light The charging system light will come on briefly when you turn the ignition on, but the engine is not running, as a check to show you the light is working. Voltmeter I /+( When your engine is not running, but the ignition is on (in the RUN position), the gage shows your battery's state of charge in DC volts. Then it should go out once the engine is running. If it stays on, orcomes on while you are driving, you may have a problem with the electrical charging system. It could indicate that you have a loose accessory drive belt, or anotherelectrical problem. Have it checked right away. Driving while this light is o n could drain your battery. If you must drive a short distance with the light on, be certain to turn off all your accessories, such as the radio and heatedair conditioner. When the ignition is running, the gage shows the condition of the charging system. Readings between the low and high warning zones indicate the normal operating range. 2-55