heater LAND ROVER DEFENDER 1996 Owner's Guide

HEATING AND VENTILATION
3
REPAIR Refit
6.Fit foam rubber to heater matrix casing.
7.Position matrix in heater unit casing.
8.Check that both vent flaps operate correctly
without sticking.
9.Secure matrix top retaining plate.
10.Secure matrix bottom retaining plates.
11.Fit heater unit
See Heater unit.RESISTOR UNIT
Service repair no - 80.20.17
Remove
1.Remove heater unit
See Heater unit.
2.Drill out 4 rivets securing resistor mounting plate
to top of volute housing.
3.Remove resistor and disconnect blower motor
plug from harness.
Refit
4.Apply Bostik adhesive to resistor mounting plate
and rivet to volute housing.
5.Reconnect blower harness motor plug.
6.Fit heater unit
See Heater unit.

80HEATING AND VENTILATION
4
REPAIR HEATER CONTROL CABLE - TEMPERATURE
CONTROL
Service repair no - 80.10.05
Remove
1.Disconnect battery.
2.Remove 4 screws securing instrument panel to
fascia cowl.
3.Pull instrument panel away from fascia and
disconnect speedometer cable to give easier
access to control cable at bulkhead.
4.Remove retaining screws and pull off air
distribution and temperature control lever knobs.
5.Remove 3 screws and detach side cover,
complete with control lever assembly.
6.Remove 2 screws securing control lever
assembly to side cover and remove cover. Note
plastic screw spacers fitted between cover and
control lever assembly and retain.
7.Remove small bolt and release outer cable
retaining clip.
8.Slacken grub screw and release inner cable from
clevis.
9.From inside engine compartment, release outer
cable retaining clip at heater unit.
10.Slacken trunnion fixing and release inner cable
from heater unit flap lever.
11.Release 2 retaining clips securing control cables
to engine bulkhead and heater hoses.
12.Pull control cable through bulkhead grommet
and remove from vehicle.
Refit
13.Fit new control cable to heater flap lever trunnion
with approximately 10 mm of inner cable
protruding from trunnion. Fully tighten trunnion.
14.Secure outer cable with retaining clip.
15.Route control cable through sealing grommet
and along inside of engine bulkhead to fascia
panel.

HEATING AND VENTILATION
5
REPAIR 16.Secure control cables to engine bulkhead and
heater hoses with retaining clips.
17.With control lever in closed position, fit inner
cable to lever clevis and fully tighten clevis grub
screw.
18.Fit outer cable retaining clip and fully tighten
securing bolt.
19.Fit side cover to control lever assembly. Ensure
fixing screw spacers are positioned between
cover and lever assembly.
20.Fit side cover to fascia.
21.Fit control lever knobs.
22.Reconnect speedometer cable and fit instrument
panel.
23.Reconnect battery.

80HEATING AND VENTILATION
6
REPAIR HEATER CONTROL CABLE - AIR DISTRIBUTION
Service repair no - 80.10.12
Remove
1.Disconnect battery.
2.Remove steering wheel
See STEERING,
Repair, Steering wheel.
3.Remove steering column nacelleSee
STEERING, Repair, Steering column nacelle.
4.Remove instrument panelSee INSTRUMENTS,
Repair, Instrument panel.
5.Remove retaining screws and pull off air
distribution and temperature control lever knobs.
6.Remove 3 screws and detach side cover,
complete with control lever assembly.
7.Remove 2 screws securing control lever
assembly to side cover and remove cover. Note
plastic screw spacers fitted between cover and
control lever assembly and retain.
8.Remove small bolt and release outer cable
retaining clip.
9.Slacken grub screw and release inner cable from
clevis.
10.Remove lower fascia panel assembly
See
CHASSIS AND BODY, Repair, Lower fascia
panel (heater duct) assembly.
11.Remove 19 screws and lift off heater duct cover.
12.Slacken vent flap trunnion fixing, release air
distribution control cable and remove from
heater duct.
13.Check condition of foam sealant on heater duct
cover and renew if necessary.

HEATING AND VENTILATION
7
REPAIR Refit
14.Fit new control cable through heater duct cover
and secure to vent flap trunnion. Bend over
cable end to fully secure.
15.Fit heater duct cover.
16.Fit lower fascia panel assembly to fascia
bulkhead
See CHASSIS AND BODY, Repair,
lower fascia panel (heater duct) assembly.
17.Route control cable along fascia bulkhead to
contol lever assembly.
18.With control lever in closed position, secure
cable to clevis.
19.Fit outer cable retaining clip to lever assembly.
20.Fit lever assembly to side cover. Ensure screw
spacers are fitted between cover and lever
assembly.
21.Fit side cover to fascia cowl.
22.Fit control lever knobs.
23.Fit instrument panel
See INSTRUMENTS,
Repair, Instrument panel.
24.Fit steering column nacelleSee STEERING,
Repair, Steering column nacelle.
CONTROL CABLE AND BLOWER MOTOR SWITCH
Service repair no - 80.10.17 - Control cable
Service repair no - 80.10.22 - Blower motor switch
Remove
1.Disconnect battery.
2.From inside engine compartment, release outer
cable retaining clip at heater unit.
3.Slacken trunnion fixing and release inner cable
from heater unit flap lever.
4.Release 2 retaining clips securing control cables
to engine bulkhead and heater hoses.
5.Remove 4 screws securing instrument panel to
fascia cowl.
6.Pull instrument panel away from fascia and
disconnect speedometer cable to ease access to
control cable.
7.Remove 2 screws securing control lever
assembly to side of fascia panel cowl. Note
plastic screw spacers fitted between cowl and
lever assembly and retain.

80HEATING AND VENTILATION
8
REPAIR
8.Release lever assembly and disconnect 3
blower motor leads, noting their positions.
9.Pull control cable through bulkhead grommet
and out from instrument panel cowl.
10.Release retaining clip securing outer cable to
lever assembly.
11.Release inner cable from lever peg.
NOTE: If the blower motor switch is faulty
the complete lever assembly will have to
be renewed.
Refit
12.Fit new control cable to lever assembly peg.
13.Fit retaining clip to secure outer cable.
14.Reconnect blower motor leads.
15.Route cable to rear of instrument panel cowl,
along bulkhead and out through grommet into
engine compartment.
16.Fit lever assembly to panel cowl. Ensure screw
spacers are fitted between cowl and lever
assembly.
17.Fit instrument panel to fascia cowl.
18.With lever in closed position, fit control cable to
heater unit flap lever trunnion.
19.Secure outer cable with retaining clip.
20.Secure control cables to engine bulkhead and
heater hoses with retaining clips.
21.Reconnect battery.

AIR CONDITIONING
1
DESCRIPTION AND OPERATION AIR CONDITIONING SYSTEM
Description
Air conditioning is an optional system which provides
fully integrated climate control for the vehicle interior.
The air conditioning system comprises four major
units as follows:- An evaporator matrix and expansion
valve (1), housed in the heater/ cooler unit (3), an
engine mounted compressor (4), a condenser (5),mounted in front of the radiator, and a receiver/drier
(7) located to the right of the condenser.
Ancillary components in the system comprise a blower
motor (2), also housed in the heater/cooler unit, and
condenser cooling fan motors (6), mounted on a
support frame. The four major units are interconnectd
by preformed metal and flexible refrigerant pipes as
illustrated below (RH drive installation shown).
Coolant flow to a heater matrix, housed in the heater
cooler unit, is controlled by a water valve (8) from a
combined air conditioning panel on the vehicle fascia.
1.Evaporator matrix and expansion valve
2.Blower motor
3.Heater/cooler unit
4.Compressor
5.Condenser6.Condenser fan motors
7.Receiver/drier
8.Water valve
9.Heater matrix feed and return hoses

82AIR CONDITIONING
2
DESCRIPTION AND OPERATION Operation
Evaporator unit and expansion valve
High pressure liquid refrigerant is delivered to the
expansion valve which is the controlling device for the
air conditioning system. A severe pressure drop
occurs across the valve and as the refrigerant flows
through the evaporator it picks up heat from the
ambient air, boils and vaporizes. As this change of
state occurs, a large amount of latent heat is
absorbed. The evaporator is therefore cooled and as
a result heat is extracted from the air flowing across
the evaporator. The refrigerant leaves the evaporator,
on its way to the compressor, as a low pressure gas.
An evaporator sensor measures the air temperature at
the evaporator and engages or disengages the
compressor clutch to prevent icing of the air ways.
Compressor
The compressor, a pump specially designed to raise
the pressure of the refrigerant, is mounted on the front
of the engine and is driven by an independent drive
belt from the crankshaft pulley. The compressor draws
vaporized refrigerant from the evaporator. It is
compressed with a resulting rise in temperature and
passed on to the condenser as a hot, high pressure
vapour.
Condenser
The condenser is mounted directly in front of the
radiator and consists of a refrigerant coil mounted in a
series of thin cooling fins to provide the maximum
heat transfer. Air flow across the condenser is induced
by vehicle movement and assisted by two electric fans
attached to the frame of the condenser. The
refrigerant high pressure vapour enters the condenser
inlet on the RH side. As the vapour passes through
the condenser coils the air flow, assisted by the two
fans, carries the latent heat away from the condenser.
This induces a change of state resulting in the
refrigerant condensing into a high pressure warm
liquid. From the condenser, the refrigerant continues
to the receiver/ drier.
Receiver/drier
This component acts as a reservoir and is used to
hold extra refrigerant until it is needed by the
evaporator. The drier within the receiver unit contains
a filter and dessicant (drying material) which absorb
moisture and prevent dessicant dust from being
carried with the refrigerant into the system.AIR CONDITIONING AND HEATER CONTROLS -
LH DRIVE
1. Temperature control
Move the lever upwards (RED) to increase air
temperature, or downwards (BLUE) to reduce air
temperature.
2. Air conditioning switch
Press the switch (indicator lamp illuminates) to
activate the air conditioning. Press again to switch off.
3. Air recirculation control
Move the lever fully upwards to activate air
recirculation. Move the lever fully downwards to
cancel recirculation.
NOTE: Prolonged recirculation may cause
the windows to mist up.
4. Air distribution control
Lever fully up - air to windscreen vents (also provides
some air to the footwell).
Lever midway - air to fascia vents (also provides some
air to the footwell).
Lever fully down - air to footwell vents (also provides
some air to the windscreen).

AIR CONDITIONING
3
DESCRIPTION AND OPERATION 5. Blower motor fan speed control
Move the lever to the right to progressively increase
fan speed.
Location of air vents - LH drive
AIR CONDITIONING AND HEATER CONTROLS -
RH DRIVE
1. Temperature control
Move the lever to the right (RED) to increase air
temperature, or to the left (BLUE) to reduce air
temperature.
2. Air conditioning indicator lamp
Illuminates when the air conditioning system is
operating.3. Air conditioning switch
Press the RH portion of the switch to activate the air
conditioning (indicator lamp illuminates). Press the LH
portion to switch off.
NOTE: Air conditioning should only be
activated when the engine is running.
4. Blower motor fan speed control
Move the lever upwards to progressively increase fan
speed.

AIR CONDITIONING
5
REPAIR RECEIVER/DRIER
Service repair no - 82.17.01
Remove
1.Disconnect battery.
2.Recover refrigerant from air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
3.Remove 6 screws and lift grille panel from
vehicle.
4.Disconnect receiver/drier dual pressure switch
multi-plug.
5.Disconnect high pressure pipe at receiver/drier.
6.Disconnect bottom union at condenser.
7.Remove retaining bolts and open clamps.
8.Release receiver/drier from condenser and
discard. It is NOT recommended to refit old unit.
9.Discard all pipe connection 'O' rings. Cap or plug
all connections to prevent ingress of dirt and
moisture.
Refit
10.Coat unions, threads and new 'O' rings with
refrigerant oil prior to reassembly.
11.Secure new receiver/drier in retaining clamp.
12.Fit receiver/drier bottom union connector at
condenser.
13.Fit high pressure pipe to receiver/drier.
14.Fit pressure switch multi-plug.
15.Evacuate and recharge air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
16.Reconnect battery.
17.Fit grille panel assembly.HEATER/COOLER UNIT - LH DRIVE
Service repair no - 82.25.21
Remove
1.Disconnect battery.
2.Recover refrigerant from air conditioning system
See Adjustment, Refrigerant recovery,
recycling, recharging.
3.Remove expansion tankSee COOLING
SYSTEM, Repair, Expansion tank
to gain
access to air conditioning high and low pressure
pipes.
4.Disconnect high and low pressure pipes. Discard
pipe connection 'O' rings. Cap or plug
connections to prevent ingress of dirt and
moisture.
5.Disconnect compressor clutch switch multi-plug.
6.Remove pipe connector from vacuum switch.
7.Remove retaining clip and disconnect control
cable from evaporator flap operating rod.
8.Remove screw and release outer cable retaining
bracket.