With Analog Cluster

Alternator and Regulator
The alternator is belt-driven from the engine. Field current is supplied from the Integral Alternator Regulator (IAR), mounted on the rear of the alternator, to the rotating field of the alternator, through two brushes and two slip rings.

The alternator produces power in the form of alternating current. The alternating current is rectified to direct current by six diodes. The alternator regulator automatically adjusts the alternator field current to maintain the alternator output voltage, within prescribed limits, to correctly charge the battery. The alternator is self-current limiting.

The regulator voltage control circuit is turned on when the ignition switch is in RUN and voltage is applied to regulator terminal I through a resistor in parallel with the charge indicator. When the ignition switch is OFF, the control circuit is turned OFF and no field current flows to the alternator.

Charge Indicator
With the ignition switch in "START" or "RUN", battery voltage is present at the charge indicator.

If the alternator is not generating power, the IC regulator inside the alternator grounds the charge indicator through circuit 904 (LG/R). The charge indicator illuminates.

When the alternator is generating power, the IC regulator inside the alternator applies battery voltage to the charge indicator through circuit 904 (LG/R). With battery voltage present at both ends of the charge indicator, there is no current flow and the charge indicator does not illuminate.