Page 6 of 1111
AC0WA±01
I03811
Smog Ventilation
Sensor
No. 2 Cooling Fan Relay
(Marking: FAN NO.2) No. 3 Cooling Fan Relay
(Marking: FAN NO.3)
CompressorMagnetic Clutch Relay
(Marking A/C COMP)
Condenser
Ambient Temperature Sensor Condenser Fan
Engine Coolant Temperature
(ECT) Switch
Air Inlet Servomotor
Blower Motor
Air Outlet Servomotor A/C Amplifier
EvaporatorSolar Sensor A/C Control Assembly
Electrical Multi Vision
(Built in A/C Control Assembly)
Expansion Valve
Air Refiner Filter
Blower Motor Control
Relay Evaporator Temperature
Sensor
Heater Radiator
Air Mix Servomotor
(Driver Side) Air Mix Servomotor
(Passenger Side)Room Temperature
Sensor
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±13
2698 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
LOCATION
Page 15 of 1111
AC0WJ±01
I02365
Instrument Panel
Reinforcement
No.2 Brace
No.1 Brace
Water Hose
Bracket
Blower Unit Liquid Tube
Suction Hose
10 (100, 7)
Defroster Nozzle
Heater to Register
Center Duct
Air Duct
Air Duct RH
Center Air Duct
Air Duct LH
O±Ring
A/C Unit
N´m (kgf´cm, ft´lbf) : Specified torque
Non±reusable part
AC±22
± AIR CONDITIONINGAIR CONDITIONING UNIT
2707 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
AIR CONDITIONING UNIT
COMPONENTS
Page 16 of 1111
I02366
Wire Harness
Packing
Packing
Tube Connector
Evaporator Temperature
Sensor
Bracket Plate
Wire Harness
O±Ring O±Ring
Tube and Accessory
4.1 (42, 36)
4.1 (42, 36)
Expansion Valve
O±Ring
Evaporator
Plate
Insulator Air Mix Servomotor
(Driver Side)
Air Outlet Servomotor
Air Duct
Cover
Drain PipeDrain Hose Air Mix Servomotor
(Passenger Side)
Heater Radiator
Blower Motor
Control Relay
N´m (kgf´cm, in.´lbf) : Specified torque
Non±reusable part
Packing
Air Duct
± AIR CONDITIONINGAIR CONDITIONING UNIT
AC±23
2708 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
Page 17 of 1111

AC0WK±01
I02360
I02361
AC±24
± AIR CONDITIONINGAIR CONDITIONING UNIT
2709 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. DISCHARGE REFRIGERANT FROM REFRIGERATION
SYSTEM
HINT:
At the time of installation, please refer to the following item.
Evacuate air from refrigeration system.
Charge system with refrigerant and inspect for leakage of refrig-
erant.
Specified amount: 600 ± 50 g (21.16 ± 1.76 oz.)
2. DRAIN ENGINE COOLANT FROM RADIATOR
HINT:
It is not necessary to drain out all coolant.
3. DISCONNECT LIQUID TUBE AND SUCTION HOSE
FROM A/C UNIT
Remove the bolt and slide the plate, then disconnect the both
tubes.
Torque: 10 N´m (100 kgf´cm, 7 ft´lbf)
NOTICE:
Cap the open fittings immediately to keep moisture or dirt
out of the system.
HINT:
At the time of installation, please refer to the following item.
Lubricate 2 new O±rings with compressor oil and install them
to the tubes.
4. DISCONNECT WATER HOSES FROM HEATER RA-
DIATOR PIPES
(a) Grips the claws of the hose clip and slide the hose clip
along the hose.
(b) Disconnect the water hose.
Page 18 of 1111
I02362
I02363
± AIR CONDITIONINGAIR CONDITIONING UNIT
AC±25
2710 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. REMOVE THESE PARTS:
(a) Cooler No.1 grommet
(b) Heater pipe grommet
(c) Drain hose grommet
(d) Instrument panel and reinforcement
(See page BO±91)
(e) Blower unit
(See page AC±30)
6. REMOVE 3 AIR DUCTS
(a) Remove the 2 screws and center air duct.
(b) Slide the floor carpet backward.
(c) Disconnect the wire harness clamps.
(d) Remove the 2 bolts and air ducts LH, RH.
7. REMOVE A/C UNIT
(a) Disconnect the connector.
(b) Remove the wire harness set nut.
(c) Disconnect the wire harness clamps.
(d) Remove the 2 nuts, bolt and A/C unit.
Page 19 of 1111

AC0WL±01
AC±26
± AIR CONDITIONINGAIR CONDITIONING UNIT
2711 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
DISASSEMBLY
1. REMOVE THESE PARTS:
(a) Wire harness
(b) Drain hose
2. REMOVE HEATER RADIATOR
(a) Remove the screw and clamp.
(b) Pull out the heater radiator.
3. REMOVE BLOWER MOTOR CONTROL RELAY
Remove the screw and blower motor control relay.
4. REMOVE AIR MIX SERVOMOTORS
Remove the 6 screws and both servomotors.
5. REMOVE AIR OUTLET SERVOMOTOR
Remove the 2 screws and servomotor.
6. REMOVE EXPANSION VALVE
(a) Pry out the packing.
HINT:
At the time of reassembly, please refer to the following item.
Do not reuse the packing.
(b) Using SST, remove the 2 bolts, then separate the expansion valve, tube connector and tube and ac-
cessory.
SST 07110±61050
Torque: 4.1N´m (42 kgf´cm, 36 in.´lbf)
HINT:
At the time of reassembly, please refer to the following item.
Lubricate 4 new O±rings with compressor oil and install them to the valve.
7. REMOVE EVAPORATOR TEMPERATURE SENSOR
(a) Disconnect the wire harness clamp.
(b) Using a screwdriver, pull out the sensor with bracket plate.
HINT:
Tape the screwdriver tip before use.
(c) Release the 2 claws and sensor from bracket plate.
8. REMOVE EVAPORATOR
(a) Using SST, remove the 2 bolts and tube and accessory.
SST 07110±61050
Torque: 4.1N´m (42 kgf´cm, 36 in.´lbf)
HINT:
At the time of reassembly, please refer to the following item.
Lubricate 2 new O±rings with compressor oil and install them to the tube.
(b) Remove the 4 screws and cover.
(c) Pull out the evaporator.
(d) Remove the plate from evaporator.
HINT:
At the time of reassembly, please refer to the following item.
If evaporator is replaced, add compressor oil to evaporator.
Add 40 cc (1.4fl.oz.)
Compressor oil: ND±OIL 8 or equivalent
9. REMOVE INSULATOR FROM HEATER CASE
10. REMOVE AIR DUCT
Remove the 4 screws and duct.
Page 51 of 1111
AC0X2±01
I02400
I02401
SST
± AIR CONDITIONINGEVAPORATOR
AC±51
2736 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
EVAPORATOR
REMOVAL
1. REMOVE A/C UNIT
(See page AC±24)
2. REMOVE HEATER RADIATOR
(See page AC±55)
3. REMOVE AIR MIX SERVOMOTOR PASSENGER SIDE
(a) Disconnect the connector.
(b) Remove the 3 screws and servomotor.
4. REMOVE TUBE AND ACCESSORY
(a) Pry out packing.
HINT:
At the time of installation, please refer to the following item.
Do not reuse the packing.
(b) Using SST, remove the 2 bolts and the tube and accesso-
ry.
SST 07110±61050
Torque: 4.1 N´m (42 kgf´cm, 36 in.´lbf)
NOTICE:
Cap the open fittings immediately to keep moisture or dirt
out of the system.
HINT:
At the time of installation, please refer to the following item.
Lubricate 2 new O±rings with compressor oil and install them
to the tube.
(c) Remove screw and drain pipe.
Page 55 of 1111
AC0X5±01
I02403
± AIR CONDITIONINGHEATER RADIATOR
AC±55
2740 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HEATER RADIATOR
REMOVAL
1. REMOVE A/C UNIT (See page AC±24)
2. REMOVE HEATER RADIATOR
(a) Remove the screw and clamp.
(b) Pull out the heater radiator.