Freelander System Description and Operation
HEATING AND VENTILATION
DESCRIPTION AND OPERATION
80-11
Operation
Air flow through the heater assembly is directed to the outlets selected by the distribution control knob. The
temperature of the air from all except the face level vents depends on the setting of the temperature control knob. Hot
air is available from the face level vents only when the temperature control knob is at the maximum heat setting. As
the temperature control knob is turned towards cold, the temperature of the air from the face level vents rapidly
decreases to ambient (non A/C vehicles) or evaporator outlet temperature (A/C vehicles). The forward speed of the
vehicle and the setting of the blower control knob determines the volume of air flowing through the system.
Air Distribution
Turning the distribution knob on the control panel turns the control flaps in the heater assembly to direct air to the
corresponding fascia and footwell outlets.
Air Temperature
Turning the temperature knob on the control panel turns the related blend flaps in the heater assembly. The blend
flaps vary the proportion of air going through the cold air bypass and the heater matrix. The proportion varies, between
full bypass/no heat and no bypass/full heat, to correspond with the position of the temperature knob.
Blower Speed
The blower can be selected 'off', or to run at one of four speeds. While the ignition is on and the blower switch is set
to positions 1, 2, 3 or 4, ignition power energises the blower relay, which supplies battery power to the blower. At
switch positions 1, 2 and 3, the blower switch also connects the blower to different earth paths through the resistor
pack, to produce corresponding differences of blower operating voltage and speed. At position 4, the blower switch
connects an earth direct to the blower, bypassing the resistor pack, and full battery voltage drives the blower at
maximum speed.
Fresh/Recirculated Inlet Air
When the recirculated air switch is latched in, the indicator LED in the switch illuminates and an earth is connected to
the recirculated air side of the fresh/recirculated air servo motor. The fresh/recirculated air servo motor then turns the
control flaps in the air inlet duct to close the fresh air inlet and open the recirculated air inlets.
When the latch of the recirculated air switch is released, the indicator LED in the switch extinguishes and the earth is
switched from the recirculated air side to the fresh air side of the fresh/recirculated air servo motor. The fresh/
recirculated air servo motor then turns the control flaps in the air inlet duct to open the fresh air inlet and close the
recirculated air inlet.
