For 1990-2009 cars

Battery voltage is applied to the ignition switch at all times through fusible link W. When the ignition switch is turned to START, battery voltage is applied to the transaxle position switch through the closed contacts of the ignition switch. If the transaxle position switch is in PARK or NEUTRAL, battery voltage is applied to the starter solenoid terminal S through the closed contacts of the transaxle position switch. When battery voltage is applied to terminal S of the starter solenoid, the hold-in coil and pull-in coil of the starter solenoid are energized with the pull-in coil grounded through the starter motor. The coils, when energized, work together to pull and hold in the plunger of the starter solenoid. As the plunger is pulled in, it closes the starter solenoid contacts and causes the shift lever to rotate, engaging the drive assembly to the engine flywheel. With battery voltage applied directly to the starter motor through the closed solenoid contacts, the starter motor begins to rotate the drive assembly as the drive assembly comes in contact with the engine flywheel. The starter motor continues to rotate to crank the engine thorough the drive assembly flywheel gear combination.

Battery voltage is removed from the starter solenoid terminal when the ignition switch is released from the START position. The pull-in and hold-in coils are de-energized and the return spring in the starter solenoid causes the plunger to disengage the drive assembly from the engine flywheel. As the plunger returns, the plunger opens the solenoid contacts removing battery voltage from the starter motor.

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

The generator's digital regulator uses digital techniques to supply the rotor current and thereby control the output voltage. The rotor current is proportional to the width of the electrical pulses supplied by the digital regulator. When the ignition switch is placed in RUN battery voltage is supplied to the generator at terminal L from the powertrain control module (PCM), turning on the regulator. Narrow width pulses are supplied to the digital rotor, creating a weak magnetic field. When the engine is started, the digital regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the digital regulator varies the field current by controlling the pulse width. This regulates the generator output voltage for proper battery charging and electrical system operation.