Condenser Fan: Description and Operation

Auxiliary Fans (M4m1 & M4m2):

PURPOSE

The auxiliary cooling fans, which are located in front of the A/C condenser, provide additional air flow across the condenser and radiator to assist during periods of high thermal load.

Relay Location:

OPERATION

Auxiliary fan activation takes place in two stages:

^ Low speed is activated by the dual function pressure switch in the receiver drier at approx. 290 psi (20 bar), via relay (K10) and a pre-resistor.

Temperature Sensor Location:

^ High speed is activated directly by the coolant temperature sensor, via relay (K9) and the ACC control unit, at approx. 224°F (107°C). When the pressure or temperature drops below preset values, fan operation discontinues.