VOLT METERS

Voltage can come from the battery or the alternator.  You need to hook it up with the + side connected to someplace in the positive side of the battery and the - side or ground.  If you connect to the positive and a non-switched line the volt meter will read voltage all the time.  Therefore we need to hook it to the ignition switch on the ignition terminal.  The voltmeter has readings of + or - for the correct wiring.

A lighted analog voltmeter will allow you to monitor the efficiency of your alternator and to a lesser extent the condition of your battery. You can therefore catch a problem before you get a long way from home or away from civilization. As an example:



A. When cranking voltage should not drop below 10 volts.
B. After starting the voltage may rise to the high side of normal until charge lost in cranking (or prior inactivity) has been replaced. Voltage should then drop slightly toward the minimum side. (Normal is 13.8--14.5 V)
C. A constant reading above 14.5 V indicates a failed voltage regulator. This high voltage will eventually destroy your battery.
D. A constant reading below 12.6 V indicates a failed voltage regulator and/or alternator. Then your battery will not maintain a charge and you will be stranded at the side of the road.