Charging System: Description and Operation

Circuit operation
When the ignition switch is turned to "ON" or "START" position, battery voltage is applied to the charge indicator and the terminal B and S of the alternator. After the engine has started and is running, the alternator produces alternating current. The alternating current flows through a series of rectifier diodes and is converted to direct current. The direct current and voltage keeps the battery fully charged and provides power to operate the vehicle's electrical system. The voltage regulator in alternator controls the amount of direct current and voltage, the alternator outputs If the voltage regulator senses that the output of the alternator is not sufficient for charging the battery, it will ground terminal L of the alternator and the charge indicator will illuminate.