The generator provides voltage in order to perform the following actions:
| • | Operate the vehicle's electrical system. |
| • | Charge the battery. |
The generator operates as an alternator in order to generate alternating current (AC) electricity. The AC electricity is then rectified to direct current (DC) electricity. A belt connected to the engine drives the generator. The generator rotates as the engine runs. The regulator induces an excitation magnetic field in the generator's rotor. The generator's rotation causes the excitation field to move through the stator windings. The motion of the field through the stator conductors generates an alternating magnetic field in the stator. The magnetic field is allowed to flow only in the one direction that would charge the battery by the diodes in the bridge rectifier. The generator's internal solid state voltage regulator regulates the pulse width of the excitation field in order to regulate the voltage generated at the BAT terminal at 13.5 V - 14.5 V.
The excitation field exists in the generator only when the ignition switch is in the RUN position or the START position. The generator does not contain permanent magnetism of sufficient strength in order to produce a usable excitation magnetic field. The generator's turn on input is present from the BRN (25) wire that connects the generator to the instrument cluster. Voltage is present to the instrument cluster from the IGN SW circuit breaker in the I/P fuse block. The BAT indicator lamp is only illuminated when sufficient current flow exists. Sufficient current flow must cause the lamp filament to emit light. The slight current flow used by the generator in normal operation is allowed by the resistor. The resistor bypasses the indicator lamp. An open filament in the lamp will not prevent generator operations.
The generator controls the BAT indicator lamp in the instrument cluster. Internal logic at the generator closes an internal contact in order to ground the indicator lamp circuit under the following conditions:
| • | The generator does not rotate. |
| • | The sensed generator output voltage is too high or too low. |
The indicator lamp circuit is only powered when the ignition switch is in the RUN position and the START position.
