Operation

Cooling Fans

OPERATION

Td4
Feed from the positive battery terminal (C0192) is supplied to fusible link 1 and the main relay (C0632) on an R wire. Both are located in the engine compartment fuse box. Operation of the main relay (C0576) is controlled by the Engine Control Module (ECM) (C0603) on a WK wire. The energized main relay provides a feed to fuse 4, which is also located in the engine compartment fuse box.

Fusible link 1 is connected in series with fusible link 7. Fusible link 7 provides a constant battery feed to the starter relay, which is also located in the engine compartment fuse box. Operation of the starter relay (C0576) is controlled by the ECM (C0059) on an PW wire. The relay coil (C0576) is earthed on a B wire. The energized starter relay (C0572) provides a feed to the E-box fan (C0646) on an NP wire.

E-box Fan
Fuse 4 of the engine compartment fuse box (C0575) provides a feed to the E-box temperature sensor (01258) on an NK wire. The temperature sensor is a thermostatic switch. When the temperature within the E-box reaches 35 °C (95 °F) the switch contact close. Current flows across the switch contacts (01258) to the E-box fan (C0646) on an NK wire. The E-box fan (C0646) is earthed on a B wire.

When the temperature within the E-box drops to 27 °C (80 °F), the switch contacts within the sensor open, cutting the feed to the E-box fan.

K Series
Feed from the positive battery terminal (C0192) is supplied to fusible link 5, and the main relay on an P wire. Both are located in the engine compartment fuse box. Fusible link 5 (C0573) provides a constant battery feed to the cooling fan relay (C0019) on an SU wire.

Operation of the main relay (C0576) is controlled by the ECM (C0913) on a WK wire. When energized, the main relay provides a feed to fuse 4, which is also located in the engine compartment fuse box. Fuse 4 (C0575) is connected to the cooling fan relay (C0019) by an NK wire.

Engine Coolant Temperature (ECT) Sensor
The ECM monitors Engine Coolant Temperature (ECT) via the ECT sensor. The ECM (C0914) provides a feed to the ECT sensor (C0169) on a KG wire. As ECT rises, the resistance of the sensor falls. By measuring the voltage returned from the ECT sensor (C0169) on a KB wire, the ECM (C0914) can determine ECT.

Cooling Fan
When the ECM (C0913) registers a temperature of 102 °C (215 °F) via the ECT sensor, it energizes the cooling fan relay by providing an earth path for the relay coil (C0019) on a UP wire. The energized cooling fan relay (C0019) provides a feed to the cooling fan motor (C0005) on an NP wire. The cooling fan motor (C0005) is earthed on a B wire.

KV6
Feed from the positive battery terminal (C0192) is supplied to fusible link 3 and the main relay (C0632) on an R wire. Both are located in the engine compartment fuse box. Operation of the main relay (C0578) is controlled by the ECM (C0371) on a WK wire. The energized main relay provides a feed to fuse 4, which is also located in the engine compartment fuse box.

Fusible link 3 (C0571) is connected to the ignition switch (C0028) by an N wire. When the ignition switch is turned to the 'ignition' position, current flows across the switch (C0028) to the E-box fan (C0646) on a WR wire.

E-box Fan
Fuse 4 of the engine compartment fuse box (C0575) provides a feed to the E-box temperature sensor (C1258) on an NK wire. The temperature sensor is a thermostatic switch. When the temperature within the E-box reaches 35 °C (95 °F) the switch contact close. Current flows across the switch contacts (C1258) to the E-box fan (C0646) on an NK wire. The E-box fan (C0646) is earthed on a B wire.

When the temperature within the E-box drops to 27 °C (80 °F), the switch contacts within the sensor open, cutting the feed to the E-box fan.