Operation, 2-Speed Radiator Fan With A/C

The radiator fan may, depending on coolant temperature, A/C pressure, car speed and outside temperature, be run at two speeds:
^ Low speed
^ High speed
The radiator fan is controlled by DICE via two relays, (155) and (81).
Irrespective of the position of the ignition switch, current is supplied to the low-speed relay (155) via fuse 3 and to the high-speed relay (81) via fuse 1.


Low speed
DICE uses the values, which fulfill the conditions for low-speed running to start the radiator fan at low speed. The relay (155) is then grounded via pin 35 of the control unit. Current is supplied to the radiator fan, which starts and runs at low speed because the current is reduced by a series resistor (367).

High speed





DICE uses the values, which fulfill the conditions for running the radiator fan at high speed. The relay (81) is then grounded via pin 53 of the control unit. As a result, the series resistor (367) is bypassed and the fan is supplied with unreduced current. The radiator fan now runs at high speed.