Principles of Operation
Principles of OperationCooling Fans
The cooling fans are controlled by 3 relays to provide 3 speeds. If DTC P0480, P0481 or P0482 are present, refer to Computers and Control Systems for diagnosis.
In HIGH speed, voltage is supplied through the following relay to engage both fans, bypassing the cooling fan resistor:
^ RH high speed cooling fan relay and LH cooling fan relay
In MEDIUM speed, voltage is supplied to the following relay to engage both fans, but goes through a cooling fan resistor:
^ RH low speed cooling fan relay and LH cooling fan relay
In LOW speed, the following relay is energized and voltage is fed to the LH cooling fan motor.
^ LH cooling fan relay