Description & Operation

Engine cooling fan system consists of 2 electric fans and one mechanical fan. Mechanical cooling fan is temperature-controlled and operated in 3 stages. Air passing through the radiator gradually heats up the bi-metal component of the fan. Fluid stored in chambers inside cooling fan flows into operating chambers inside fan, causing fan motion to increase as temperature rises. See Figure. Electric cooling fans are controlled by relays between engine, A/C system and a coolant temperature sensor. Primary electric fan is activated when coolant reaches 93°C and shuts off when coolant temperature drops below 83°C. Secondary electric fan is activated when A/C refrigerant pressure reaches a specified pressure to provide additional cooling for the engine.