The charging system consists of an alternator containing a rectifier pack and regulator to maintain a constant direct current (dc) voltage in the system. The alternator is belt driven from the crankshaft and cooled by a fan mounted behind the pulley. The alternator has a fixed coil wound stator in which a field coil rotor rotates. Slip rings conduct current to and from the field coils via 2 carbon brushes. The regulator senses output voltage and controls this to approximately 14 volts.
Charging
Feed from the positive battery terminal is connected to fusible link 2 (C632-1) of the engine compartment fuse box by a brown wire. Fusible link 2 (C907-2) supplies a feed to the ignition switch (C28-1 ) on a brown wire and the starter relay (C151-87), also on a brown wire.
With the ignition switch in position "II" (C094-1), a feed is supplied to the ignition coil (C156-1) and the ignition amplifier module (C633-3) on white wires. The ignition switch also provides a feed to the ignition/no charge warning lamp (C230-4) on a white wire. The warning lamp is earthed (C230-5) via the diode (C118-1 ) on a yellow/brown wire and through the alternator field windings (C185-1) on a brown/yellow wire. The flow of current through the warning lamp and field windings partially magnetises the rotor. A resistor (C038-1 & C037-1) is wired in parallel with the warning lamp to ensure continued exciter voltage in the event of bulb failure.
When the engine starts, the magnetised rotor rotates within the stator windings, generating a 3 phase alternating current (a.c.) and voltage which rises rapidly with rotor speed. The field diodes convert the a.c. current to direct current (d.c.) and the generated voltage is fed back to the field windings. As the feed back voltage increases, the magnetic influence of the rotor also increases, resulting in self-excitation of the rotor. Generated current and voltage increases with rotor speed until the alternator is fully excited.
When the alternator outputs a voltage equal to that supplied by the battery, the warning lamp is extinguished as the potential difference across the lamp is 0 volts. The diode between the alternator and warning lamp prevents reverse flow.
The regulator functions as an electronic control switch on the earth side of the field coils. The regulator rapidly switches the earth circuit off and on to control the generated voltage and current to safe limits.
If the battery is in a low state of charge or current draw from the electrical system is high and causes a voltage drop, the alternator charges at its maximum rate until 14 volts is generated. As battery voltage rises, the generator current output reduces.
Starting
Feed from the positive battery terminal is connected to the engine compartment fuse box (C632-1) by a brown wire. Fusible link 2 (C907-2) then provides a constant battery feed to the ignition switch (C028-1) and the starter relay (C151-87). Both are connected by brown wires.
Fuel Supply
With the ignition switch in position "II" (C094-1), a feed is supplied to the fuel pump relay (C298-85) on a white wire. The relay is connected (C298-86) on a white/brown wire to the oil pressure switch (C187-1). When the engine is not turning over, there is no oil pressure. In this condition, the oil pressure switch is in the "closed" position. This provides an earth path and energises the fuel pump relay.
The ignition switch (C094-1) also provides a feed to pin 87A of the fuel pump relay (C298-87A) on a white wire. With the oil pressure switch in the "closed" position, the energised fuel pump relay is unable to provide a feed to the fuel pump (C115-2)
When the ignition switch is turned to the "crank" position (090-1), it provides a feed to the starter relay coil (C151-85) on a white/red wire. The relay is earthed (C151-86) on a black wire. Feed from fusible link 2 (C907-2) of the engine compartment fuse box can now flow across the starter relay (C151-87 & C151-30). Current flows from the starter relay (C151-30) to the similarily energised fuel pump relay (C298-87) on a white/red wire. The fuel pump relay (C2298-30) then provides a feed to the fuel pump (C115-2) on a white/purple wire. The fuel pump is earthed (C115-3) on a black wire.
With the engine running, and the ignition switch turned back to position "II" (C094-1), the oil pressure switch will sense oil pressure. This opens the switch and de-energises the fuel pump relay. Feed to the fuel pump is now provided solely by the fuel pump relay.
Ignition
With the ignition switch in position "II", a feed is supplied to the ignition coil (C156-1) and the ignition amplifier module (C633-3). Both are supplied current on white wires and are connected in parallel. An earth path is provided by the ignition amplifier module fixings.
When the ignition switch is turned to the "crank" position, power flows across the switch (C090-1) to the starter relay (C151-85) on a white/red wire. The relay is earthed (C151-86) on a black wire. This flow of current energizes the relay coil and allows a battery feed to flow across the relay (C151-87 & C151-30) and onto the starter motor (C179-1) on a white/red wire. This feed energizes the starter solenoid, and allows a feed from the alternator (C178-1) on a brown wire to operate the starter motor. An earth is provided by the starter motor.