heating LAND ROVER DISCOVERY 1999 Repair Manual

HEATING AND VENTILATION
80-24REPAIRS
Heater assembly - models with air
conditioning
$% 80.20.01.98
Remove
1.Drain cooling system.
l

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
l

+ COOLING SYSTEM - Td5,
ADJUSTMENTS, Drain and refill.
2.Evacuate air conditioning system.

+ AIR CONDITIONING, REFRIGERANT
RECOVERY, RECYCLING AND
RECHARGING, Refrigerant recovery,
recycling and recharging.
3.Release 2 clips securing heater hoses to
heater and release hoses.
4.Remove 2 bolts securing air conditioning pipes
to evaporator, release pipes and discard 'O'
rings.
CAUTION: Always fit plugs to open
connections to prevent contamination.
5.Remove fascia.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Fascia.6.Remove screws securing rear heater ducting
and remove ducting.
7.Disconnect multiplug from heater motor.
8.Remove 2 nuts and bolt securing heater motor
assembly and remove motor assembly from
heater casing.

HEATING AND VENTILATION
REPAIRS 80-25
9.Remove 2 screws securing centre console
support bracket and remove bracket.
10.Remove 2 nuts securing RH fascia support
bracket and remove bracket. 11.Disconnect both evaporator drain hoses.
12.Remove front heater ducting.
13.Remove 4 nuts and bolt securing heater
assembly, release heater assembly from
bulkhead grommet and remove from vehicle.
Refit
1.Position heater assembly to bulkhead, locate
heater in bulkhead grommet.
2.Fit nuts and bolt securing heater and tighten to
16 Nm (12 lbf.ft).
3.Position RH fascia support bracket, fit and
tighten nuts.
4.Fit front heater ducting.
5.Position centre console support bracket, fit and
tighten screws.
6.Connect evaporator drain hoses.
7.Position heater motor to heater casing, fit nuts
and bolt and tighten to 19 Nm (14 lbf.ft).
8.Connect multiplug heater motor.
9.Position rear heater ducting and secure with
screws.
10.Fit fascia.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Fascia.
11.Using new 'O' rings, position air conditioning
pipes to evaporator fit bolts and tighten to 5 Nm
(3.7 lbf.ft).
12.Position heater hoses and secure hose clips.
13.Recharge air conditioning system.

+ AIR CONDITIONING, REFRIGERANT
RECOVERY, RECYCLING AND
RECHARGING, Refrigerant recovery,
recycling and recharging.
14.Refill cooling system.
l

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
l

+ COOLING SYSTEM - Td5,
ADJUSTMENTS, Drain and refill.

HEATING AND VENTILATION
80-26REPAIRS
Blower assembly
$% 80.20.12
Remove
1.Remove 4 studs securing toe board and
remove toe board.
2.Remove 4 screws securing glove box, release
catch and remove glove box.
3.Disconnect battery earth lead.4.Disconnect multiplugs from blower motor.
5.Remove 8 bolts securing passenger side of
fascia panel.
6.Carefully ease fascia away from bulkhead
7.Remove 3 bolts securing blower motor support
bracket and remove bracket.
8.Remove 2 nuts securing motor assembly.
9.Release blower motor assembly from heater
and manoeuvre from under fascia.
Refit
1.Position blower motor assembly under fascia
and locate to heater casing.
2.Position support bracket, fit and tighten nuts
and bolts.
3.Align fascia, fit bolt to support bracket and
tighten to 26 Nm (19 lbf.ft).
4.Connect multiplugs to blower motor.
5.Connect battery earth lead.
6.Fit glove box, align hinges and tighten screws.
7.Position toe board and secure with studs.

HEATING AND VENTILATION
REPAIRS 80-27
Motor - blower
$% 80.20.15
Remove
1.Remove 4 studs securing toe board and
remove toe board.
2.Remove 4 screws securing glove box, release
catch and remove glove box. 3.Remove screw securing harness to blower
motor and release harness.
4.Disconnect multiplug from blower motor.
5.Remove 3 screws securing blower motor to
casing and remove blower motor.
Refit
1.Position blower motor to casing and secure
with screws.
2.Connect multiplug to blower motor.
3.Position harness and secure clip with screw.
4.Fit glove box, align hinges and tighten screws.
5.Position toe board and secure with studs.

HEATING AND VENTILATION
80-28REPAIRS
Resistor pack - power resistor A/C
$% 80.20.17
Remove
1.Remove 4 studs securing toe board and
remove toe board.
2.Remove 4 screws securing glove box, release
catch and remove glove box. 3.Disconnect multiplug from resistor.
4.Remove screws securing resistor, release and
remove resistor.
Refit
1.Position resistor and secure with screw.
2.Connect multiplug to resistor.
3.Position glove box, fit and tighten screws.
4.Position toe board and secure with studs.

HEATING AND VENTILATION
REPAIRS 80-29
Heater matrix
$% 80.20.29
Remove
1.Remove heater assembly.

+ HEATING AND VENTILATION,
REPAIRS, Heater assembly - models with
air conditioning.
2.Remove 2 screws securing coolant pipe
saddles and remove saddles.
3.Loosen screws securing coolant pipes to
matrix, release clamps and remove coolant
pipes.
4.Remove and discard 'O' rings.
5.Remove heater matrix.
Refit
1.Position heater matrix, using new 'O' rings fit
coolant pipes and align clamps.
2.Fit saddle clamps and secure with screws
3.Tighten coolant pipe clamp screws.
4.Fit heater assembly.

+ HEATING AND VENTILATION,
REPAIRS, Heater assembly - models with
air conditioning.
Pipe - Heater - Feed
$% 80.25.07
Remove
1.Remove heater return pipe.

+ HEATING AND VENTILATION,
REPAIRS, Pipe - Heater - Return.
2.Release clip securing heater feed hose to
heater feed pipe and disconnect hose from
pipe.
3.Remove nut securing heater feed pipe to
plenum chamber.
4.Press quick release connector and release
heater feed pipe from plenum chamber.
5.Remove and discard 'O' ring from pipe.
Refit
1.Fit new 'O' ring to heater feed pipe and lubricate
with castor oil.
2.Secure heater feed pipe to plenum chamber.
3.Fit and tighten nut securing heater feed pipe to
plenum chamber.
4.Connect heater feed hose to heater feed pipe
and secure with clip.
5.Fit heater return pipe.

+ HEATING AND VENTILATION,
REPAIRS, Pipe - Heater - Return.
M80 0435
23
4

HEATING AND VENTILATION
80-30REPAIRS
Pipe - Heater - Return
$% 80.25.12
Remove
1.Drain engine coolant.

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
2.Release clip securing heater return hose to
heater return pipe and disconnect hose from
pipe.
3.Remove bolt securing heater return pipe to
heater feed pipe.
4.Release clips securing engine harness and
vacuum pipe to heater return pipe.
5.Remove bolt securing heater return pipe to
cylinder head.
6.Release clip securing engine coolant hose to
heater return pipe.
7.Release engine coolant hose from heater
return pipe and collect pipe.Refit
1.Connect engine coolant hose to heater return
pipe and secure with clip.
2.Position heater return pipe to cylinder block and
secure with bolt.
3.Secure engine harness and vacuum pipe to
heater return pipe and secure with clips.
4.Fit and tighten bolt securing heater return pipe
to heater feed pipe.
5.Connect heater return hose to heater return
pipe and secure with clip.
6.Refill engine coolant.

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
M80 0437
M80 0438
4
46
7
5

HEATING AND VENTILATION
REPAIRS 80-31
Fuel burning heater - (FBH) - Td5
$% 80.40.01.99
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.Clamp feed and return coolant hoses at FBH.
4.Position container to collect spillage.
5.Release clips, disconnect coolant feed and
return hoses from FBH.
CAUTION: Before disconnecting or
removing components, ensure the
immediate area around joint faces and
connections are clean. Plug open
connections to prevent contamination.
6.Disconnect 2 multiplugs from FBH.7.Position container to collect spillage and
disconnect quick release fuel pipe from FBH.
CAUTION: Before disconnecting any part of
the fuel system, it is imperative that all dust,
dirt and debris is removed from around
components to prevent ingress of foreign
matter into fuel system.
8.Remove Torx bolt securing FBH to bulkhead
mounting bracket.
9.Release and remove FBH.
10.Collect locating bushes from pegs.
Refit
1.Fit bushes to pegs.
2.Align FBH to pegs, fit Torx bolt and tighten to 25
Nm (18 lbf.ft).
3.Clean quick release connection and fit fuel pipe
to FBH.
4.Connect multiplugs to FBH.
5.Connect coolant hoses to FBH and secure with
clips.
6.Release clamps from hoses.
7.Connect battery earth lead.
8.Fit and secure battery cover.
9.Top-up cooling system.

+ MAINTENANCE, PROCEDURES,
Cooling system.

AIR CONDITIONING
DESCRIPTION AND OPERATION 82-3
Description
General
The air conditioning system controls the temperature, distribution and volume of air supplied to the vehicle interior to
provide a comfortable cabin environment. The system is electronically controlled and features automatic and manual
modes of operation, with separate temperature control of the LH and RH air outlets. The automatic modes provide
optimum control of the system under most ambient conditions and require no manual intervention. The manual modes
allow individual functions of automatic operation to be overridden, to accommodate personal preferences.
The air conditioning system consists of a refrigerant system, a heater assembly and a control system. It also uses the
same air inlet duct and distribution ducts as the Heating and Ventilation system on non air conditioned vehicles.

+ HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.
Fresh or recirculated inlet air flows into the heater assembly from the blower in the air inlet duct. In the heater
assembly, the air is cooled and/or heated, depending on the selected cabin temperature and ambient conditions, then
directed to selected air outlets.
On vehicles with rear air conditioning, additional cooling is provided by recirculating air through a second evaporator
and distributing it to outlets in the roof.

+ AIR CONDITIONING, DESCRIPTION AND OPERATION, Description.

AIR CONDITIONING
DESCRIPTION AND OPERATION 82-9
Heater assembly
1Distribution servo motor
2Refrigerant inlet and outlet connector block
3RH blend flap servo motor4Thermostatic expansion valve
5LH 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:
lThe thermostatic expansion valve, evaporator and evaporator temperature sensor are installed at the air inlet
side of the casing.
lThree servo motors operate the control flaps instead of control cables.
lA 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.