Voltmeter with Ignition ON
at 12 Volts
Voltmeter with Engine Running
at 14 Volts
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.