Radiator Cooling Fan Motor: Description and Operation

The electric fan system consists of a fan and electric motor. This system uses a coolant temperature switch, mounted in the thermostat housing, to sense coolant temperature. Vehicles equipped with A/C have a cooling fan controller and a cooling fan relay. On Tempo and Topaz models equipped with a standard heater, the cooling fan is powered through the cooling fan relay.
On Tempo and Topaz models, the cooling fan is wired to operate only when the ignition switch is in the Run position. On Escort models, the cooling fan will run whenever the cooling fan temperature switch is closed.
On vehicles equipped with A/C, the cooling fan motor will be energized whenever the A/C cycling pressure switch closes, with the select lever in the A/C or Defrost position. The A/C clutch coil will be energized once voltage is supplied to the fan motor. The A/C clutch will cycle with the A/C clutch cycling pressure switch. The fan motor will stay energized as the clutch cycles, if the cycling pressure switch ``open intervals'' are less than 2-3 minutes. If the coolant temperature switch closes in the A/C mode at approximately 210°F, the fan motor will run until coolant temperature drops below approximately 193°F.