GMC 1993 Safari Owner's Manual page 123

Charging System Light
Standard Cluster Digital Cluster
I
r
4
PO647
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 heater/air conditioner.
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