A voltmeter measures
electrical system pressure in volts. A voltmeter only needs
to tap into an electrical circuit (we are tapped into the
power to the Fuel Gauge). Voltmeter installation is easy,
quick, and safe: It hooks up to a fused, ignition-switched "off/on" source.
The voltmeter directly
measures the result of charging-system performance. With
normal alternator/voltage-regulator function, battery voltage
is maintained at 14.0 to 14.5 volts-and this is reported
directly by the voltmeter. In the event of alternator-system
failure, voltage will be low and continue to drop as the
battery discharges. In the event of an "overcharge" condition,
the voltmeter will climb above its normal zone.
NOTE:
Fuel Gauge points straight up because it has power but no
signal.