Operation

STARTING OPERATION

Main relay operation
With the ignition switch in position II and the ECM is satisfied that all conditions are correct, the ECM grants an earth path on a UR wire from the engine compartment fusebox to the ECM pin C0635-23 energising the relay coil and closing the contacts.

Fuel pump relay operation
When the main relay contacts are closed, the feed direct from the battery passes through the relay contacts and is connected to the coil of the fuel pump relay. An earth path from the fuel pump coil is connected to the ECM pin C0635-18 on a UP wire. When the ECM completes the earth path, the coil energises and closes the fuel pump relay contacts.

The feed from fuse 10 passes through the contacts of the fuel pump relay and is connected on a WP wire from the engine compartment fusebox to the fuel pump, which operates The fuel pump is connected to earth eyelet connector C0810-1 on a B wire.

Starter relay operation
When the ignition switch is moved to the crank position III, a feed passes from fuse 23 to the coil of the starter relay in the engine compartment fusebox on a WR wire.

The coil is earthed to the BCU on a BO wire When the BCU determines that starter operation is allowed, the earth path is completed and the starter relay energises, closing the relay contacts.

The feed from fusible link 12 passes through the starter relay contacts and is connected from the engine compartment fusebox to the coil of the starter motor solenoid on an NR wire. The coil energises closing the starter motor solenoid contacts The coil is earthed via the starter motor body

The feed from the battery positive terminal passes through the closed contacts of the starter motor solenoid and operates the starter motor. The starter motor is earthed through the motor body attachment.

When the ignition switch is released, it returns to position II. This terminates the feed from the ignition switch to the starter relay coil de-energising the coil and opening the relay contacts. This, in turn removes the feed from fusible link 12 to the starter motor solenoid coil, opening the contacts and removing the battery feed to the starter motor.

CHARGING OPERATION
With the ignition switch in position II, the feed from fuse 27 is connected from the passenger compartment fusebox on an LG wire through header C0760 to the ignition/no charge warning lamp in the instrument pack From the instrument pack the feed is connected on an NY wire to the alternator / generator. The feed passes to earth via the brushes and regulator within the alternator completing the warning lamp circuit which allows the warning lamp to illuminate.

When the engine is started, the magnetized rotor turns within the stator windings, generating 3 phase alternating current (ac) and a voltage that rises rapidly with rotor speed. The field diode in the rectifier pack converts the ac current into dc current flowing through the field windings This causes an increase in the magnetic influence of the rotor resulting in self-excitation of the alternator. The field current increases with rotor speed and thus increases the generated current and voltage until the alternator/generator is fully excited

When the voltage applied to the alternator/generator side of the ignition/no charge warning lamp exceeds the battery voltage applied to the warning lamp the lamp is extinguished. This shows that the alternator/generator is producing battery charging current.

When the battery is at a low state of charge or the current draw from the electrical functions of the vehicle causes a voltage drop the alternator / generator automatically charges at its maximum rate (dependant on rotor speed) until 14 volts Is reached. When demand on the alternator/generator falls, the current output is reduced.

Battery charging is accomplished on an N wire from the alternator/generator through fusible link 1 in the engine compartment fusebox, and from fusible link 1 to the battery positive terminal on an R wire.