Expedition 4WD V8-5.4L SOHC VIN 5 (2005)
Housing Assembly HVAC: Description and Operation
PLENUM CHAMBER
The plenum chamber directs airflow from the blower motor through the evaporator core and heater core. All airflow from the blower motor passes
through the evaporator core. Airflow is then directed through or around the heater core by the temperature blend door(s). Vehicles equipped with DATC
use a partitioned plenum chamber with two electric actuator-positioned temperature blend doors. This allows for separate temperatures to be selected for
the driver and passenger sides of the passenger compartment. Manual systems use a single electric actuator-positioned temperature blend door to direct
airflow through or around the heater core.
