GMC 1998 Savana Van Owner's Manual page 127

Voltmeter
When your engine is not
on (in the RUN position),
this gage shows your
DC volts.
\ \ \
I
I /
/I,
running, but the ignition is
9 19
battery's state of charge in
VOLTS
I
W
When the engine is running, the gage shows the
condition of the charging system. Readings between the
low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur wnen a
large number
of
electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power at
engine idle. As engine speeds
are
increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.
You can only drive for a short time with the reading in
either warning zone. If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
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