1995 LAND ROVER DISCOVERY Workshop Manual

76CHASSIS AND BODY
70
REPAIR
8.Remove the securing bolt and detach the inertia
reel from the bottom of the 'B' post.9.Release the seat belt sensor connector (if fitted).
10.Release Torx bolt to allow removal of the seat
belt stalk assembly.
Refit
11.Reverse removal procedure.
NOTE: Ensure the seat belt is not twisted.
12.Re-connect the seat belt sensor connector (if
fitted).
13.Finally, tighten the seat belt fixings to
32 Nm (24
lbf ft)
.

HEATING AND VENTILATION
1
DESCRIPTION AND OPERATION HEATING AND VENTILATION UNIT
The heating and ventilation and blower units are
standard on all models. Air conditioning system is an
optional module, which when fitted provides fully
integrated climate control for the vehicle interior.
The heating and ventilation unit controls the air
distribution and heating to the vehicle interior. The
blower unit controls the volume of air supplied, while
the air conditioning module (when fitted) provides
refrigerated and dehumidified air.
1. Fresh air inlet
2. Recirculation air inlet
3. Air outlets screen de-mist
4. Air outlet face level vents
5. Air outlets front footwells
6. Air outlets to rear footwells7. Fresh/recirculation air flap servo
8. Blower motor relay
9. Multiplug connector to main harness
10. Multiplug connector, blower to heater unit
11. Resistor unit - blower speed.

80HEATING AND VENTILATION
2
DESCRIPTION AND OPERATION Through-flow ventilation
Through-flow ventilation is achieved by means of
one-way air extraction vents incorporated in both rear
quarter body panels. The vents open and close
automatically dependent upon the heating and
ventilation unit control settings and the volume of air
entering the vehicle.Heating and ventilation unit, controls
The Heating and Ventilation Unit is centrally located
and concealed by the dash assembly. When air
conditioning is fitted, an evaporator is mounted in the
heater unit forward of the heater matrix.
The dash mounted central controls are used to
operate both systems. A single switch controls the air
conditioning unit when fitted.
Controls set for maximum heat to footwells and face level vents
Heating and ventilation flaps and air flow key
1. Fresh or recirculated air from blower unit
2. Evaporator matrix - air conditioning (when fitted)
3. Heater matrix
4. Air outlet front footwells
5. Air outlet to rear footwells
6. Air outlet face level vents7. Air outlets screen de-mist
8. Control flap - face level vents
9. Control flap - demist vents
10. Control flap - air direction
11. Control flap - air temperature
12. Control flap - air direction

HEATING AND VENTILATION
3
DESCRIPTION AND OPERATION
Controls set for unheated air to footwells and face level vents
Heater and ventilation operation
The heating and ventilation system contains a heater
matrix, which is connected to the engine cooling
system, and a 4 speed fan for air distribution. Engine
coolant is circulated through the heater matrix
continuously, except when the temperature controls
are set to COLD.
Recirculated air
When the recirculation switch is pressed, an electrical
servo operates and fully closes the fresh air intake
flap.
Fresh air
When the recirculation switch is returned to the OFF
position, the electrical servo returns and fully opens
the fresh air intake flap.Heated air
Temperature output is controlled by the temperature
controls which move the air direction and temperature
flaps independently to increase or decrease the
volume of air flow through the heater matrix.
V8 Engine:When both controls are in the cold
position, the coolant valve is turned off.
Face level vent flap
Control at face level, flap fully open. All other vents
closed.
Control at face and foot level, flaps half open.
Unless an air conditioning unit is fitted, only fresh or
re-circulated air is available from the face level vents.
Demist vent flap
Control at demist, flap fully open. All other vents
closed.
Control at demist and foot level, flaps half open.

80HEATING AND VENTILATION
4
DESCRIPTION AND OPERATION Air direction flap
Flap moves across mixing chamber to direct the air
flow away from the heater matrix.
Air temperature flap
Control at HOT, flaps fully closed. All air flow passes
through heater matrix. As control is moved towards
COLD the flaps progressively open directing air flow
away from the heater matrix.
Control at COLD, flaps fully open.
V8 Engine:When both controls are at COLD, 2
micro-switches are closed and operate a vacuum
valve which closes the coolant valve.Air conditioning
When an air conditioning unit is fitted, the mechanical
operation of the heater controls remains unaltered.
However the air conditioning evaporator is positioned
in front of the mixing chamber through which all air
flow passes.

HEATING AND VENTILATION
1
FAULT DIAGNOSIS HEATER OUTPUT
Symptom:-
Heater emits cold air.
1.Engine running: Check coolant valve opens as a
temperature control is moved from COLD.
2.Check for engine running cold.
See COOLING
SYSTEM, Fault diagnosis, Engine Runs Cold
3.Check heater pipes and hoses for blockage or
restriction.
4.Check heater matrix for blockage or restriction,
flush system.
Heater emits warm air.
5. Engine running:Check coolant valve closes
when both temperature controls are moved to
COLD.

HEATING AND VENTILATION
1
REPAIR HEATER BLOWER SWITCH AND ILLUMINATION
BULB
Service repair no - 80.10.22 - Switch
Service repair no - 86.48.73 - Bulb
Remove
1.Pull 3 knobs from rotary controls.
2.Pull knob from blower switch.
3.Remove 2 screws retaining graphics panel.
4.Remove graphics plate.
5.Remove capless bulb.
6.Remove 4 screws retaining switch.
7.Remove switch panel. Use plastic tube to assist
removal.
Blower switch
8.Pull blower switch from rear of panel.
9.Disconnect multiplug and remove blower switch.
Refit
10.Reverse removal procedure.HEATER CONTROL UNIT
Service repair no - 80.10.42.
Remove
1.Disconnect battery negative lead.
2.Pull 3 knobs from rotary controls.
3.Pull knob from blower switch.
4.Remove 2 retaining screws and remove
graphics panel.
5.Remove 4 screws retaining switch.
6.Remove switch panel.
7.Release fascia centre louvre vent panel from its
fitted position to gain access to rear of panel.
See CHASSIS AND BODY, Repair, Dash
Panel Central Louvre Panel

80HEATING AND VENTILATION
2
REPAIR 8.Disconnect 4 multiplugs and position harness
aside.
NOTE:Do not carry out further
dismantling if component is removed for
access only.
9. Fan speed switch:remove fan speed switch
slide and push out fan speed switch.
10.Pull out light bulb disconnect terminals and
remove fan speed light strip.
11.Unclip 3 heater control cables from control unit.
12. Microswitch:Unclip 3 micro switches.
13.Cut cable tie and release wiring harness from
control unit.
14.Remove heater control unit.
Refit
15.Reverse removal procedure. Check the
satisfactory function of the controls before fitting
louvre vent panel.CONTROL CABLES
Service repair no - 80.10.06 - Air flow
Service repair no - 80.10.25 - Temperature control
RH
Service repair no - 80.10.26 - Temperature control
LH
Remove
1.Release fascia centre louvre vent panel from its
fitted position to gain access to rear of panel.
See CHASSIS AND BODY, Repair, Dash
Panel Central Louvre Panel
2.Open glove box, manoeuvre side springs
through cut-outs and lower lid.