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 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 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 52 of 1111
I02402
AC±52
± AIR CONDITIONINGEVAPORATOR
2737 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. REMOVE EVAPORATOR
(a) Disconnect the connector from blower motor control
relay.
(b) Remove the screw and drain hose.
(c) Remove the 4 screws and cover.
(d) Pull out the evaporator.
HINT:
At the time of installation, please refer to the following item.
If evaporator is replaced, add compressor oil to evaporator.
Add 40 cc (1.4 fl. oz.)
Compressor oil: ND±OIL 8 or equivalent
Page 64 of 1111
AC0XE±01
I02406
I02407
AC±64
± AIR CONDITIONINGBLOWER MOTOR CONTROL RELAY
2749 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
BLOWER MOTOR CONTROL
RELAY
REMOVAL
1. REMOVE THESE PARTS:
(a) Front door scuff plate RH
(b) Cowl side trim RH
(c) No.2 under cover
(d) Glove compartment door
(e) Glove compartment panel
(See page BO±91)
2. REMOVE AIR DUCT
Remove the 3 screws and duct.
3. DISCONNECT WIRE HARNESS
4. REMOVE BLOWER MOTOR CONTROL RELAY
Remove the screw and blower motor control relay, then discon-
nect the connectors.
Page 65 of 1111
AC0XF±01
± AIR CONDITIONINGBLOWER MOTOR CONTROL RELAY
AC±65
2750 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
INSPECT BLOWER MOTOR CONTROL RELAY CIRCUIT
(See page DI±1126)
Page 66 of 1111
AC0XG±01
AC±66
± AIR CONDITIONINGBLOWER MOTOR CONTROL RELAY
2751 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
Installation is in the reverse order of removal (See page AC±64).
Page 79 of 1111

Z19533
32 1
541
43 2
5AC0XQ±01
I050271 2
5
1235
3
N23635
3
2
15
4
± AIR CONDITIONINGRELAY
AC±79
2764 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
RELAY
INSPECTION
1. INSPECT HEATER MAIN RELAY
(Marking: HTR) CONTINUITY
ConditionTester connectionSpecified condition
Constant2 ± 4
1 ± 3Continuity
Apply B+ between
terminals 1 and 3.5 ± 4Continuity
If continuity is not as specified, replace the relay.
2. INSPECT MAGNETIC CLUTCH RELAY
(Marking: A/C COMP) CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
3. INSPECT No.2 COOLING FAN RELAY
(Marking: FAN NO.2) CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2
3 ± 4Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
4. INSPECT No.3 COOLING FAN RELAY
(Marking: FAN NO.3) CONTINUITY
Check the relay in the same way as for ºMAGNETIC CLUTCH
RELAYº.