Ford 1996 Aerostar Manual page 83

Battery Voltage Gauge (Voltmeter)
This gauge shows you the battery voltage when
the ignition key is in the ON position.
If you are running electrical accessories (when
the engine is off, or idling at a low speed), the
pointer may move toward the lower end of the
normal band. If it stays outside the normal band
area, have your vehicle's electrical system
checked as soon as it is safely possible.
If the battery is operating under cold weather
conditions, the pointer may indicate in the upper
range of the NORMAL band while the battery is
charging. If you are running electrical accessories
with the engine off or idling at a low speed, or
the battery is not fully charged, the pointer may
move toward the lower end of the NORMAL
band.
If it stays outside the NORMAL band, have your
vehicle's electrical system checked as soon as it
is safely possible.
Battery voltage gauge
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