Legend Coupe V6-2675cc 2.7L SOHC FI (1988)
Radiator Cooling Fan Motor: Description and Operation
Coupe
FANS
The radiator fan control unit controls the operation of the radiator and A/C condenser fans. It uses inputs from the radiator fan temperature sensor,
A/C dual pressure switch A, and A/C high pressure switch B to determine when the fans will run and at what speed.
OPERATION
When the engine oil temperature is above 221 degrees F (105 degrees C) and the engine is not running, the A/C condenser fan will run to cool
the engine for a maximum of 30 minutes or when the engine oil temperature falls below 194 degrees F (90 degrees C).
COMPRESSOR CONTROL
The A/C system consists of the A/C switch in the heater - A/C control panel, evaporator sensor, radiator fan control unit, coolant temperature
switch, A/C pressure switches, electronic control unit, A/C compressor clutch relay and A/C compressor clutch.
OPERATION
When the A/C switch and the blower switch are turned on, the radiator fan control unit monitors the evaporator sensor temperature through the
closed contacts of the A/C dual pressure switch A. If the evaporator sensor temperature is above 39 degrees F ( 4 degrees C), the radiator fan
control unit energizes the fans and sends a signal to the electronic control unit. The electronic control unit increases engine idle speed and
energizes the A/C compressor clutch. When evaporator temperature drops below 37 degrees F (3 degrees C), the electronic control unit turns off
the fans and A/C compressor clutch.
If the refrigerant pressure becomes too high due to blockage or too low due to leakage, A/C dual pressure switch A contacts open to prevent the air
conditioner from operating.
When the pressure is high due to heavy operation in high temperature, A/C pressure switch B contacts close and the fans run at a higher speed. If
engine coolant temperature exceeds 234 degrees F (112 degrees C), the air conditioner will shut off.
