Condenser Fan: Description and Operation

AUXILIARY COOLING FANS AND CONTROL

Auxiliary Fan Relay (K9):

Auxiliary Fan Resistor (R15), High Pressure Switch (S32):

Control Of The Cooling Fans Occurs In Two Stages:
Stage 1
- With the compressor engaged, outside temperature above 15 ° C and vehicle speed below 40 km/h (25 mph).
- The auxiliary fans are activated by the control unit via the relay (K9) and the resistor (R15). The fans are switched off at speeds above 70 km/h (44 mph).

Coolant Temperature Sensor (B10/8):

Stage 2
- With the compressor engaged and coolant temperature above 107 ° C or a refrigerant pressure greater than 20 bar. Temperature induced actuation occurs via the coolant temperature sensor (B10/8) and the auxiliary fan relay (K9).
- Pressure induced actuation occurs via refrigerant high pressure switch (S32) and auxiliary fan relay (K9).