The engine cooling fan system consists of one cooling fan and two relays. The cooling fan has 2 windings in the motor, one winding is for low speed and the other winding is for high speed. Voltage is supplied to the relays fuses. The engine control module (ECM) controls the low speed fan operation by grounding the relay control circuit. When the relay is energized, voltage is delivered to the cooling fan low speed winding. The ECM controls the high speed fan operation by grounding the relay control circuit. When the relay is energized, voltage is delivered to the cooling fan high speed winding. The cooling fan motor is grounded through its own ground circuit.

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the engine control module (ECM) to operate both fans together at low or high speeds.

During low speed operation, the ECM supplies the ground path for the K2 relay through the relay control circuit. This energizes the K2 relay coil, closes the relay contacts, and supplies battery positive voltage from the fuse through the cooling fan motor supply voltage circuit to the right cooling fan. The ground path for the right cooling fan is through the K10 relay and the left cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the ECM supplies the ground path for the K2 relay through the K2 relay control circuit. The ECM grounds the K11 relay and the K10 relay through the relay control circuits. This energizes the K10 relay coil, closes the relay contacts, and provides a ground path for the right cooling fan. At the same time the K11 relay coil is energized closing the relay contacts and provides battery positive voltage from the fuse on the cooling fan motor supply voltage circuit to the left cooling fan. During high speed fan operation, both engine cooling fans have their own ground path. The result is a parallel circuit with both fans running at high speed.

Refer to Engine Cooling Schematics .