Charging System: Description and Operation

CIRCUIT OPERATION
The charging system is an integral part of the battery and starter systems. Since these systems work together, any diagnosis and testing should be done in conjunction.

The charging system is protected by a 10 gauge fusible link located in the A11 circuit. The A11 circuit is connected to the battery feed bus bar of the [1][2]Power Distribution Center (PDC) and the generator.

The generator is case-grounded through its attaching bracket. This generator uses a voltage regulator internal to the Powertrain Control Module (PCM).

When the vehicle is running, battery voltage is applied to the generator field terminal through the A142 circuit on all engine applications. This circuit is controlled by the contact side of the Automatic Shut-Down (ASD) relay. The ground, or voltage regulated side, of the generator field is controlled by the K20 circuit. Circuit K20 connects to cavity 4 of the PCM.

When there is current present in the field, and the rotor is turning, the stator in the generator produces a B+ voltage that is supplied to the battery through the A11 and A0 circuits. The A11 circuit is connected to the output terminal of the generator and the battery feed bus bar of the PDC. The A0 circuit is a direct battery feed from the battery to the PDC.

Grounding for the system is accomplished at the battery negative terminal. These grounds go to the engine and body.