Charging System: Description and Operation

OPERATION

Alternator
The alternator is belt-driven by 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 a series of 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.

Regulator
The Regulator voltage control circuit is turned on when the ignition Switch is "ON" and voltage is applied to Regulator terminal I through a resistor in parallel with the alternator warning indicator. When the ignition Switch is "OFF", the control circuit is turned off and no field current flows to the alternator.

Warning Indicator
The alternator warning indicator is connected across the terminals of a 500-ohm resistor at the instrument cluster. Current passes through the indicator when the ignition switch is in "RUN" and there is no voltage at terminal S. When voltage at terminal S rises to a preset value, the regulator switching circuits stop the flow of current into terminal I, and the indicator turns off.

System voltage is sensed at Regulator terminal A. The regulator switching circuits turn the warning indicator on to indicate a system fault if terminal A voltage is excessively high or low, or if the voltage at terminal S is below a preset value.

Fuse Link
A fuse link is included in the charging system. The fuse link prevents damage to the wiring harness and alternator if the wiring harness should become grounded, or if a booster battery is improperly connected to the charging system.