Radiator Cooling Fan Motor: Description and Operation

The engine cooling fan is designed to lower engine operating temperatures and is installed on models with air conditioning. A thermal switch (also a thermal vacuum valve and micro-switch are used on some models equipped with engine cooling fan ignition advance system) located in the lower radiator hose controls the engine cooling fan operation. The engine cooling fan operates when engine coolant temperature reaches approximately 212°F and is switched OFF when coolant temperature drops below 203°F. Some models also incorporate an ignition advance system which is directly controlled (ignition timing advanced) when the engine cooling fan is engaged.