Chevrolet 1994 Astro Passenger Owner's Manual page 119

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. Then it should go out once the engine is running. If it stays on, or
comes 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 another electrical problem. Have it checked right away. Driving while
this light is on could drain your battery.
The charging system light is on the left bottom corner of your standard
cluster. It is part of the digital cluster voltmeter.
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.
2-59