Alternator: Description and Operation

PURPOSE

The electronic controller regulates the the charging system voltage within a range of 12.9 to 15.0 volts.

OPERATION

The electronic controller also controls ASD relay operation. The input for the ASD relay comes from the engine speed sensor through the controller. When the engine running speed is above 384 rpm, a signal is sent from the electronic controller to engage the ASD relay, which supplies alternator field control. When rpm drops below 320, the signal to the ASD relay is dropped, opening the alternator field circuit.