For 1990-2009 cars

Refer to Starter and Charging, Cell 30 in Electrical Diagnosis for information on the charging system.

Important: The generator does not require periodic maintenance.

### Wiring Connections

In addition to the ground path through the generator housing and engine, the generator uses 3 wiring connections:

• | The output terminal connects to battery positive, and is hot at all times.

• | Generator terminal L is connected to the PCM. The connection is through harness terminal B in the 4-way generator connector.

| If the built-in regulator detects a charging system fault, the regulator grounds this circuit. Grounding the circuit signals the PCM to light the charge indicator in the instrument cluster.

• | Generator terminal F is connected internally to the generator field. Terminal F is also connected to the PCM through harness terminal C in the 4-way generator connector.

| The PCM monitors this circuit for fault detection. Monitoring lasts from the time the engine is turned ON until the engine starts. As long as the duty cycle signal in this circuit indicates that the generator is not operating, the PCM lights the charge indicator.

| When the duty cycle first indicates that the generator is operating, the PCM turns OFF the charge indicator. The PCM then switches fault detection monitoring to the L circuit.

### Charge Indicator

The charge indicator in the instrument cluster turns ON if the ignition is ON and the engine is not running. When the engine starts, the indicator should turn OFF. If the indicator turns ON and remains ON when the engine is running, there is a fault in the charging system. The charge indicator does not identify what type of fault the PCM detects. The charge indicator also turns ON while the engine is running if the system voltage is too high or too low.

### Voltage Regulator

The regulator voltage setting varies with temperature. It limits system voltage by controlling rotor field current while the field current is ON. The regulator actually switches rotor field current ON and OFF at a fixed frequency in order to help control radio noise. The frequency is about 400 cycles per second. The regulator obtains the correct average field current for proper system voltage control by varying the overall ON/OFF time of the rotor field current. At high speeds the ON-time may be 10%, with 90% OFF-time. At low speeds, with high electrical loads, the ON/OFF time may be 90%/10%.