Electric Cooling Fan

On many models, PCM regulates operation of electric cooling fan through a PCM-controlled cooling fan relay which controls the ground circuit or power circuit for the cooling fan. This allows PCM to operate cooling fan based upon engine coolant temperature. Most systems will engage electric cooling fan whenever A/C clutch is engaged, regardless of engine temperature. A malfunction of the cooling fan will cause engine overheating and possible detonation.

Some models use more than one cooling fan. The second fan may function as an auxiliary cooling device when A/C is engaged or (on models using A/C high and low pressure switches) during periods of engine overheating, or high A/C refrigerant pressures.

For component application and related wiring, see appropriate ELECTRIC COOLING FANS article in ENGINE COOLING.