Discovery II
AIR CONDITIONING
DESCRIPTION AND OPERATION
82-9
Heater assembly
1 Distribution servo motor
2 Refrigerant inlet and outlet connector block
3 RH blend flap servo motor
4 Thermostatic expansion valve
5 LH blend flap servo motor
The heater assembly controls the temperature and distribution of air supplied to the distribution ducts, and is similar
to the heater assembly installed in non A/C vehicles.
HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description. The only differences from
the heater assembly in non A/C vehicles are as follows:
l
The thermostatic expansion valve, evaporator and evaporator temperature sensor are installed at the air inlet
side of the casing.
l
Three servo motors operate the control flaps instead of control cables.
l
A coolant temperature sensor is installed against the heater matrix.
The servo motors are controlled by the ATC ECU. Feedback potentiometers in the servo motors provide the ATC ECU
with flap position signals.