The generator features the following major components:

The pulley and the fan cool the slip ring and the frame.

The generator features permanently lubricated bearings. Service should only include tightening of mount components. Otherwise, replace the generator as a complete unit.

The voltage regulator controls the rotor field current in order to limit the system voltage. When the field current is on, the regulator switches the current on and off at a rate of 400 cycles per second in order to perform the following functions:

At high speeds, the on-time may be 10 percent with the off-time at 90 percent. At low speeds, the on-time may be 90 percent and the off-time 10 percent.

The generator provides DC voltage to operate the vehicle's electrical system and to charge the battery. A magnetic field is created when current flows through the rotor windings. The rotor is belt driven by the engine creating an AC voltage as this field rotates within the stator windings. The AC voltage is converted to DC voltage by the rectifier bridge and is then supplied to the electrical system at the generator battery terminal.

When the engine is running, the generator turn-on signal is sent to the generator from the powertrain control module (PCM), turning on the regulator. The generator's voltage regulator controls the current flow to the rotor, thereby controlling the generator output voltage. The rotor current is proportional to an electrical pulse width modulated voltage supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This regulates the generator's output voltage for proper battery charging and electrical system operation. The system voltage sense circuit receives B+ voltage that is Hot At All Times. This voltage is used by the regulator as the reference for system voltage control.

The PCM controls the Charge indicator on the instrument panel cluster (IPC) by sending a GM LAN message to the body control module (BCM) which then sends the message to the IPC as class 2 serial data. The Charge indicator will turn on whenever the PCM detects the following condition: