An HVAC system for work vehicle having an operator compartment for an
operator is disclosed. The HVAC system includes a pressurizer blower and
an air-conditioning system coupled to an electronic circuit. The
electronic circuit is configured to reduce the output of the pressurizer
blower when the operator selects a high output from the air-conditioning
system. The HVAC system is also configured to provide defog operation in
both a manual mode and an automatic mode of operation. The HVAC system is
configured to reset the defog operation when the vehicle ignition is
turned off or turned back on. The HVAC system is also configured not to
reset the defog operation when the operator switches rapidly between the
automatic mode and the manual mode of operation.