Charging

Charging

The battery (C1641) provides a permanent feed to the alternator (C0183) via the starter motor (C0178) on an R wire. Fuse 5 of the passenger compartment fuse box (C0587) provides an ignition feed to the alternator (C0053) on a GW wire.

When the engine is cranked, the alternator (C0053) supplies the ECM (C0606) a Pulse Width Modulated (PWM) signal on a U wire. The ECM uses this PWM signal to calculate the electrical load on the alternator, and controls engine idle speed accordingly.

When the engine is started, the magnetised rotor within the stator windings generate 3 phase alternating current (ac) and voltage that rises rapidly with rotor speed. The field diodes in the rectifier pack convert the ac current into direct current (dc). Output current from the field diodes supplements the initial current flowing through the field windings. This causes an increase in the magnetic influence of the rotor, resulting in self-exitation of the alternator. The field current increases with rotor speed and thus increases the generated current and voltage until the alternator is fully excited. The alternator (C0178) charges the battery (C1641) by providing current on an R wire.