Radiator Cooling Fan: Description and Operation

1908 Electric Fans 1 and 2 for the Cooling System







Electric fan 1 has a maximum power of 600 watts, electric fan 2 of 300 watts, For continuous control, the DME control module changes the duty cycle for the end stages of fans 1 and 2.

Control of fan speed is dependent on coolant and ambient temperature. The coolant thermostat begins to open at about 83 degrees C (182 degrees F) coolant temperature and reaches its maximum opening at about 98 degrees C (21O degrees F). The two stepless fans 1 and 2 ate activated at about 93 degrees C (2OO degrees F) and reach their full performance at about 105 degrees C (220 degrees F).

With the air-conditioning switched on, the fans are also activated, above a pressure of about 20 bar (294 PSI) in the air-conditioning system maximum fan demand is reached. Above a coolant temperature of > 118 degrees C (245 degrees F) the air-conditioning compressor is switched off (zero delivery).

Above 125 km/h (78 MPH), the speed of both fans is reduced and at 140 km/h (87 MPH) they are completely switched off, however whenever coolant temperature rises above 116 degrees C (245 degrees F), they are switched on again and off again at below 105 degrees C (220 degrees F).