Alternator Lamp/Indicator: Description and Operation
OPERATIONThe alternator warning indicator is connected across the terminals of a 500-ohm resistor at the instrument cluster. When the ignition switch is in "RUN", the regulator diagnostic circuit will activate the alternator warning indicator. The alternator warning indicator will stay illuminated until the alternator stator sends a signal to the regulator diagnostic circuit indicating that the alternator is generating current.
System voltage is sensed at Regulator terminal A. The regulator diagnostic circuit will turn the warning indicator on to indicate a system fault if terminal A voltage is excessively high or low.