landrover Workshop Repair Guides

Land Rover Workshop Service and Repair Manuals

AIR CONDITIONING|ATC ECU > < Distribution Ducts
Page 368
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AIR CONDITIONING

DESCRIPTION AND OPERATION

82-19

Air Distribution

Forced Ventilation Outlets
The forced ventilation outlets promote the free flow of air through the passenger compartment. The outlets are 
installed in the LH and RH rear quarter body panels and vent passenger compartment air into the sheltered area 
between the rear quarter body panels and the rear bumper.

Rear Blower (High Line System Only)
The blower is installed between the front seats, in the rear face air duct, and consists of an open hub, centrifugal fan 
powered by an electric motor. Operation of the electric motor is controlled by a thumbwheel on the rear passenger 
face vent via the ATC ECU and an output stage (voltage amplifier) installed in the outlet of the fan.

The thumbwheel operates a variable potentiometer which outputs between 1.25 V (blower off) and 5 V (maximum 
blower speed) to the ATC ECU. The ATC ECU then outputs a proportional control voltage between 0 and 5 V to the 
output stage, which regulates a battery power feed from the rear blower relay to the blower to produce the related 
blower speed.

The rear blower relay is installed in the rear fusebox and energised while the ignition is on.

AIR CONDITIONING|ATC ECU > < Distribution Ducts