A/c-Heater System - Automatic Land Rover Range Rover II

SPECIFICATIONS

SPECIFICATIONS

DESCRIPTION

Automatic climate control A/C-heating system consists of 4 major components: evaporator, compressor, condenser, and receiver-drier. All components are connected by preformed aluminum and flexible refrigerant lines.

With AUTO button depressed, all heating, ventilation and air conditioning systems are automatically controlled utilizing signals from ambient and in-car temperature sensors, along with solar sensor. Information from these sensors is transmitted to A/C-heater control panel Electronic Control Unit (ECU) which adjusts temperature and fan speed settings. (Scheme 1)and (Scheme 2).

Scheme 1

Blower Motor (Fan) Control

Fan speed is controlled by center knob on A/C-heater control panel. Clockwise rotation increases fan speed. Fan speed control is cancelled when defrost is selected.

Defrost Control

Defrost button operates vent flap, directing full fresh air to windshield and side windows. Heated front and rear window LEDs will illuminate. Temperature and fan speed will be set to maximum.

Temperature Control

The A/C-heater system utilizes separate temperature rotary controls for left and right sides of vehicle. Temperature variation is achieved by separate servo motor-operated vent flaps within air distribution unit.

Fresh/Recirculated Air Control

Press recirculated air button for recirculated air. Servo motor will close vent flap in both air inlet housings and switch LED will illuminate. Recirculate air function is cancelled if recirculated air button is pressed again or if defrost mode is selected.

Scheme 2

AIR CONDITIONING FAULTS

Note. This section covers mechanical and possible fuse faults that could occur in the air conditioning system. Visual checks of components within the system and relevant fuses should be carried out before undertaking detailed fault diagnosis procedures using TestBook/T4. For details of possible faults to vent flap servo motors that are common to heating, ventilation and air conditioning systems, see HEATING & VENTILATION FAULTS .

Air Conditioning System Inoperative

AIR CONDITIONING SYSTEM INOPERATIVE

Blower Motors Inoperative Or Slow Running

BLOWER MOTORS INOPERATIVE OR SLOW RUNNING

Blower Motor Vibration

BLOWER MOTOR VIBRATION

Compressor Clutch Inoperative

COMPRESSOR CLUTCH INOPERATIVE

Compressor Clutch Noisy

COMPRESSOR CLUTCH NOISY

Condenser Fan Motor Inoperative Or Slow Running

CONDENSER FAN MOTOR INOPERATIVE OR SLOW RUNNING

Condenser Fan Motor &/Or Condenser Vibration

CONDENSER FAN MOTOR &/OR CONDENSER VIBRATION

HEATING & VENTILATION FAULTS

Note. This section covers mechanical, fuse and possible flap servo motor faults that could occur in the heating and ventilation system. Visual checks of components within the system and relevant fuses should be carried out before undertaking detailed fault diagnosis procedures using TestBook/T4.

Note. Should any fault occur in the heating and ventilation system on vehicles equipped with air conditioning, a "BOOK" and "!" symbol will be displayed on the switch control panel.

Heating & Ventilation System Inoperative

HEATING & VENTILATION SYSTEM INOPERATIVE

Heater Emits Cold Air Only, Driver Or Passenger Sides

HEATER EMITS COLD AIR ONLY, DRIVER OR PASSENGER SIDES

Heater Emits Hot Air Only, Driver Or Passenger Sides

HEATER EMITS HOT AIR ONLY, DRIVER OR PASSENGER SIDES

Heater Emits Hot Or Cold Air To Demist Only

HEATER EMITS HOT OR COLD AIR TO DEMIST ONLY

Heater Emits Hot Or Cold Air To Fascia & Footwell Vents Only

HEATER EMITS HOT OR COLD AIR TO FASCIA & FOOTWELL VENTS ONLY

Heater Emits Hot Or Cold Air To Fascia Vents Only

HEATER EMITS HOT OR COLD AIR TO FASCIA VENTS ONLY

Heater Emits Hot Or Cold Air To Footwell Only

HEATER EMITS HOT OR COLD AIR TO FOOTWELL ONLY

Heater Emits Recirculate Air Only

HEATER EMITS RECIRCULATE AIR ONLY

Heater Emits Ambient Air Only

HEATER EMITS AMBIENT AIR ONLY

Individual Heating & Ventilation Functions Inoperative When Switch Controls Are Used

INDIVIDUAL HEATING & VENTILATION FUNCTIONS INOPERATIVE WHEN SWITCH CONTROLS ARE USED

No Boosted Air Supply To Heater Distribution Unit

NO BOOSTED AIR SUPPLY TO HEATER DISTRIBUTION UNIT

Poor Air Supply From Distribution Unit To Demist, Fascia Or Footwell Vents

POOR AIR SUPPLY FROM DISTRIBUTION UNIT TO DEMIST, FASCIA OR FOOTWELL VENTS

Refrigerant System Checks

For any refrigeration system to function efficiently all components must be in good working order. The system cooling cycle and the relationship between air discharge temperature and ambient temperature and the pressures at the compressor can help in determining the correct operation of the system. The length of any cooling cycle is determined by such factors as ambient temperature and humidity, thermostat setting, compressor speed and air leakage into the cooled area, etc. With these factors constant, any sudden increase in the length of the cooling cycle would be indicative of abnormal operation of the air conditioning system.

The low and high side pressures at the compressor will vary with changing ambient temperature, humidity, in-car temperature and altitude.

Where the efficiency of the refrigerant system is suspect, carry out a system performance test. See A/C SYSTEM PERFORMANCE under TESTING. The following components should be checked before operating the system

1. Drive belt tension.
2. Compressor clutch operation.
3. Blower motor operation.
4. Condenser unit fins. Build up of dirt will cause poor cooling and higher operating temperatures.
5. Air filter elements. A blocked filter will restrict cooling of the evaporator and it is, therefore, important to renew both filters at the recommended service schedule.

The following conditions should be checked after operating the system for several minutes

1. All high pressure lines should be hot to the touch.
2. All low pressure lines should be cool to the touch.
3. Inlet and outlet temperatures at the receiver-drier should be at the same temperature (warm). Any noticeable temperature difference would indicate a blocked receiver-drier.
4. Heavy frost on the expansion valve inlet would indicate a defective valve or moisture in the system.

Head Pressure - High

HEAD PRESSURE - HIGH

Head Pressure - Low

HEAD PRESSURE - LOW

Insufficient Cooling

INSUFFICIENT COOLING

Noisy Expansion Valve (Steady Hissing)

NOISY EXPANSION VALVE (STEADY HISSING)

Suction Pressure - High

SUCTION PRESSURE - HIGH

Suction Pressure - Low

SUCTION PRESSURE - LOW

TESTING

A/C SYSTEM PERFORMANCE

1. Park vehicle out of direct sunlight. Start engine and allow it to idle at 1000 RPM. Set A/C controls to outside air, panel (vent) mode, full cold, and A/C button on.
2. Set blower/fan on high speed and close windows. Operate system for 8-10 minutes to allow system to stabilize. Gradually increase engine speed to 1800 RPM. Insert thermometer in center vent, and measure air discharge temperature. Temperature must be 48-66°F (9-19°C) at center vent, with high side low pressures within specification. See «SPECIFICATIONS»(/land-rover/range-rover/ii-1994-2002/remont/automatic-hvac-system/#ac-heater-system-automatic) table.

REMOVAL & INSTALLATION

DISCONNECTING BATTERY

Note. Some Land Rover models may be equipped with a anti-theft alarm back-up battery. Before disconnecting main battery, turn ignition on and then off. Main battery must be disconnected within 17 seconds or anti-theft alarm will be activated using back-up battery.

Before disconnecting negative battery, obtain radio presets and anti-theft code for radio from vehicle owner. When radio is disconnected from battery power it will not operate when power is restored until anti-theft code is entered. See appropriate ENTERTAINMENT SYSTEM article in ACCESSORIES & EQUIPMENT for procedure. Other vehicle systems (if equipped) affected by disconnecting battery may be electric windows and sun roof, trip computer, trip odometer and remote security handsets. See appropriate system reset procedures before disconnecting battery.

Disconnect negative battery cable. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Release drive belt tension. Remove belt from compressor. Disconnect compressor electrical connector. Remove inlet and outlet lines from compressor. Remove compressor mount bolts. Remove compressor. To install, reverse removal procedure.

Move front seats as far back as possible. Remove driver and passenger-side center console panels. Remove 4 A/C-heater control unit screws. Disconnect electrical connectors. Remove A/C-heater control unit. (Scheme 3) To install, reverse removal procedure.

Scheme 3

Removal & Installation (Recirculation Servo)

Disconnect electrical connector. Remove 2 recirculation flap servo screws. Remove servo. To install, reverse removal procedure.

Removal & Installation (Blend & Distribution Servo)

Remove heater unit. See HEATER UNIT . Remove 2 rear vent duct screws. Remove duct. Unclip wiring harness and disconnect electrical connector. Remove 2 servo-to-heater case screws. Remove servo. To install, reverse removal procedure.

Remove underhood air intake panels. Remove plastic cover, nut and washers from left wiper spindle. Disconnect heated windshield left electrical connector. Remove 6 bolts from panel to left of wiper motor. Remove panel. (Scheme 4) Remove air/pollen filter. To install, reverse removal procedure.

Scheme 4

Ambient temperature sensor is located under air/pollen filter. See AIR/POLLEN FILTER . Turn sensor counterclockwise and unclip from recirculation flap housing. To install, reverse removal procedure.

Disable air bag system. See AIR BAG RESTRAINT SYSTEMS article. Remove glove box. Remove wiring harness from firewall clips. Remove lower instrument panel cover. Remove cruise control ECU bracket bolts. Move ECU aside. Move air bag harness aside. Disconnect blower motor connector. Remove 4 blower motor screws. Remove blower motor and fan assembly. (Scheme 5) To install, reverse removal procedure.

Scheme 5

Removal & Installation (Gasoline)

1. Disconnect negative battery cable. Remove front grille. Remove front bumper. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Remove 5 hood latch panel screws. Remove hood release cable clips. Remove hood latch panel.
2. Disconnect 2 condenser fan electrical connectors. Remove 4 condenser-to-fan bolts. Remove fans. Remove oil cooler left air deflector. Disconnect condenser inlet and outlet lines. Remove condenser-to-condenser mount bolts. Remove condenser. To install, reverse removal procedure.

Scheme 6

1. Disconnect negative battery cable. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Remove battery. Remove 2 screws securing diesel injection ECU cover and remove cover. (Scheme 6)
2. Remove 2 screws securing ECU harness clamp. Remove and position ECU and positive battery cable away from battery box. Remove 4 bolts securing battery box and remove battery box from vehicle.
3. Remove front grille. Remove 4 bolts holding hood support. Remove hood release cable clips from hood latch panel. Remove hood latch panel. Disconnect intercooler hoses. Remove 2 bolts securing intercooler to condenser. Remove 4 bolts securing intercooler to radiator bracket. Remove intercooler.
4. Remove 2 studs securing left deflector panel and remove panel. Remove 2 bolts securing condenser to radiator bracket. Remove 2 nuts securing clips and refrigerant lines to condenser fans. Disconnect refrigerant lines from condenser. Raise condenser for access. Remove 2 condenser fan wiring harness connectors. Remove condenser assembly. Remove condenser securing bolts from condenser. Remove 4 bolts securing fans to condenser and remove fans.
5. To install, reverse removal procedure. Install condenser fans to condenser. Connect wiring harness connectors to fans. Clean surface of refrigerant lines, lubricate new "O" rings with compressor oil, and connect lines to condenser. Evacuate and charge A/C system.

Evaporator and heater temperature sensors are located behind glove box. Open glove box. Remove 5 glove box liner screws. Disconnect glove box light electrical connector. Release glove box latch cable. Lower glove box liner to gain access to evaporator and heater temperature sensors. Disconnect electrical connector from sensor(s). Remove sensor(s). To install, reverse removal procedure.

Remove heater unit. See HEATER UNIT. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Remove screw inside center vent duct. Remove 2 evaporator-to-heater unit screws. Remove evaporator from heater unit. (Scheme 7) To install, reverse removal procedure.

Scheme 7

Remove heater unit. See HEATER UNIT . Remove 2 right heater duct screws. Remove heater duct. Remove heater pipe bracket screws. Remove 2 right servo screws. Remove right servo. Remove 2 heater core-to-heater case clips. Remove heater core and pipe assembly. Remove pipe assembly from heater core. To install, reverse removal assembly.

1. Release instrument panel mountings and support instrument panel with wood blocks. See «INSTRUMENT PANEL»(/land-rover/range-rover/ii-1994-2002/remont/automatic-hvac-system/#ac-heater-system-automatic__instrument-panel). Remove panel vents from both sides of instrument panel. Slide duct vents away from heater unit. Remove passenger-side blower duct.
2. Remove 4 A/C-heater control panel screws. Disconnect electrical connectors and remove A/C-heater control panel. Remove 5 screws from center console electrical components. Remove center console electrical components to access heater forward mount bolts.
3. Disconnect solar sensor and alarm LED electrical connectors. See «SOLAR SENSOR»(/land-rover/range-rover/ii-1994-2002/remont/automatic-hvac-system/#ac-heater-system-automatic). Release clip securing wiring harness to ducting. Move wiring harness aside. Release coolant temperature sensor-to-heater core inlet pipe clip. Move solar sensor aside. Disconnect evaporator sensor electrical connector.
4. Remove 2 instrument panel-to-heater unit wiring harness clips. Remove 4 heater unit-to-instrument panel frame bolts. With an assistant, hold wiring harness away from heater. Remove heater unit from instrument panel. (Scheme 8) To install, reverse removal procedure.

Scheme 8

INSTRUMENT PANEL

Note. Instrument panel removal requires removal of center console and steering column.

1. Disable air bag system. See AIR BAG RESTRAINT SYSTEMS article. Remove battery. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Drain cooling system. Disconnect heater hoses. Remove electric window remote switches from center console.
2. Disconnect rear footwell light electrical connector. Remove console bin base. Remove rear console-to-floor stud nuts. Move both front seats rearward. Remove both side panels from console.
3. Remove screw from rear of shift lever bezel. Unclip 2 springs at front edge of shift lever bezel. Disconnect cigarette lighter electrical connector. Disconnect cigarette lighter bulb. Remove shift lever bezel.
4. On manual transmission equipped vehicles, remove gearshift knob. Remove 2 front console floor bolts. On automatic transmission equipped vehicles, remove 2 selector lever screws. Remove selector lever. Remove 3 selector plate screws. Remove selector plate. (Scheme 9)
5. On all vehicles, remove parking brake lever clevis pin clip. Remove clevis pin. Raise parking brake lever to vertical position. Lift rear of console to disengage rear vent ducts. Remove center console.
6. Remove intermediate steering shaft in engine compartment. Disconnect driver-side footwell light plug. Remove lower steering column panel. Remove steering column covers. Remove turn indicator switch stalk-to-column screws. Remove indicator stalk. Remove wiper switch stalk-to-column screws. Remove wiper switch stalk. Disconnect ignition switch, rotary coupler (clockspring), and air bag system electrical connectors.
7. Remove 2 air bag-to-steering column harness clips. Disconnect steering column electrical connectors. Remove driver-side blower motor housing duct. Remove driver-side duct. Remove 2 steering column-to-firewall screws. Remove 2 steering column-to-brake pedal bolts. Remove steering column assembly.
8. Remove wiper motor and linkage. Disconnect passenger-side heated windshield electrical connector. Remove panel to left of wiper motor. (Scheme 4) Remove pollen filters located under side panel. Remove pollen filter housings. Remove radio. Pull off lower "A" pillar door seal. Remove driver-side foot rest. Remove driver and passenger-side kick panels.
9. Remove fuse compartment cover from driver-side seat base trim. Remove driver-side seat base trim. Remove driver-side sill plate. Remove both lower instrument panel covers. Remove 4 instrument panel center bracket bolts. Remove center bracket. (Scheme 10)
10. Disconnect Body Control Module (BCM) electrical connectors. Disconnect main air bag electrical connector. Disconnect electrical connectors at "A" pillar. Disconnect electrical connectors and vacuum lines at brake and clutch switches.
11. Remove both front wheelwell liners. Remove air cleaner baffle under left wheelwell. Disconnect both air bag crash sensor connectors. Remove battery tray bolts. Remove air cleaner-to-inner fender bolts. Raise air cleaner and battery tray to access air bag sensor harness clips. Detach air bag harness clips. Route air bag harness through inner fender panel, into wheelwell, and through firewall.
12. Remove pipe clamp at Thermostatic Expansion Valve (TXV). Remove A/C lines and "O" rings from TXV. Remove 4 instrument panel-to-firewall bolts. Remove instrument panel-to-"A" pillar nuts and washers. Remove instrument panel-to-pedal assembly bolt. With an assistant, carefully remove instrument panel out through driver's door. To install, reverse removal procedure.

Scheme 9

Scheme 10

1. Interior temperature sensor is located in center console, behind grille. Move front seats fully rearward. Remove side panels from center console. Remove radio and A/C-heater control panel bezel. Remove 5 center console panel screws. Slide out center console components.
2. Disconnect interior temperature sensor connector. Remove 2 interior temperature sensor screws. Remove interior temperature sensor. (Scheme 11) To install, reverse removal procedure.

Scheme 11

Pry solar sensor from central defrost vent. Disconnect solar sensor electrical connector. (Scheme 12) To install, reverse removal procedure.

Scheme 12

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Automatic A/C-Heater System Wiring Diagram (1997-98 Range Rover - 1 Of 2). Scheme 29

Automatic A/C-Heater System Wiring Diagram (1997-98 Range Rover - 2 Of 2). Scheme 30

See also:
• COMPUTER RELEARN PROCEDURES
• HEATING & VENTILATION FAULTS
• A/C SYSTEM PERFORMANCE
• SPECIFICATIONS
• INSTRUMENT PANEL