Page 80 of 1111

AC0Y2±01
I03743
1 2 AC±80
± AIR CONDITIONINGCONDENSER FAN
2765 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
CONDENSER FAN
ON±VEHICLE INSPECTION
1. INSPECT CONDENSER FAN OPERATION
Inspect the fan operation, as shown in the chart below.
Test conditions:
Ignition switch ON
Blower speed control switch position ºHIº
Temperature control dial at ºMAX. COOLº
Install manifold gauge setº
A/C switch ON
ConditionFan operation (Fan speed)
Engine coolant temperature
91°C (196 °F) or belowRotate (Low speed)
Engine coolant temperature
100°C (212 °F) or aboveRotate (High speed)
Refrigerant pressure is less than
1,520 kPa (15.5 kgf´cm2, 220 psi)Rotate (Low speed)
Refrigerant pressure is 1,520 kPa
(15.5 kgf´cm2, 220 psi) or aboveRotate (High speed)
If operation is not as specified, proceed to the next inspection.
2. INSPECT CONDENSER FAN MOTOR OPERATION
(a) Disconnect the fan connector.
(b) Connect the positive (+) lead from the battery to terminal
2 and negative (±) lead to terminal 1 then check that motor
operations smoothly.
If operation is not as specified, replace the fan mo-
tor.
If operation is as specified, check the pressure
switch, cooling fan relays and engine coolant temp.
switch.
Page 141 of 1111
BE0GS±10
I01362
Defogger WireIgnition SwitchDefogger Switch
Defogger Switch
Mirror Assembly
Mirror Defogger
LEXUS navigation
System
Passenger Side
Junction Block
DEF M±Fuse
MIR HTR Fuse
Mirror Defogger Relay
Mirror Assembly
Mirror Defogger
Passenger Cowl Side
Relay Block
Defogger Relay
± BODY ELECTRICALDEFOGGER SYSTEM
BE±107
2408 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
DEFOGGER SYSTEM
LOCATION
Page 142 of 1111

BE0GT±03
I04112
6
I04113
I04114
Wire Harness Side
Connector ºAº Connector ºBº
I01200
2 1
35
2 5
1 3
BE±108
± BODY ELECTRICALDEFOGGER SYSTEM
2409 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT DEFOGGER TIMER OPERATION
(a) Connect the positive (+) lead from the voltmeter to termi-
nal 6 of body ECU No.1 connector and negative (±) lead
to body ground.
(b) When the switch is OFF, the voltage should be approx.
12V.
(c) Turn the defogger switch ON and check that the indicator
lights up and that the voltage is less than 1 V.
(d) After 15 minutes, check that the switch is OFF and the
voltage is approx. 12 V.
If operation is not as specified, replace the switch.
2. INSPECT DEFOGGER SWITCH (in PANEL SWITCH)
CIRCUIT
Connector disconnected:
Disconnect the connector from the panel switch and inspect the
connector on wire harness side, as shown in the chart.
Tester connectionConditionSpecified condition
B10 ± GroundConstantContinuity
A1 ± GroundConstantBattery voltage
A2 ± GroundIgnition switch LOCKNo voltage
A2 ± GroundIgnition switch ACC or ONBattery voltage
If the circuit is not as specified, replace the switch.
3. INSPECT DEFOGGER RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
4. INSPECT DEFOGGER RELAY CIRCUIT
(See page DI±812 and BE±21)
Page 143 of 1111

I01200
2 1
35
2 5
1 3
I01291
Tester Probe
Tin FoilHeat Wire
I01292
At Center
I01293
0 Volts
Broken
WireSeveral
Volts
Battery
side Ground sideFoil strip
± BODY ELECTRICALDEFOGGER SYSTEM
BE±109
2410 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. INSPECT MIRROR DEFOGGER RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
6. INSPECT MIRROR DEFOGGER RELAY CIRCUIT
(See page BE±21)
7. INSPECT DEFOGGER WIRE
NOTICE:
When cleaning the glass, use a soft, dry cloth, and wipe the
glass in the direction of the wire. Take care not to damage
the wires.
Do not use detergents or glass cleaners with abrasive in-
gredients.
When measuring voltage, wrap a piece of tin foil around the
tip of the negative probe and press the foil against the wire
with your finger, as shown.
(a) Turn the ignition switch ON.
(b) Turn the defogger switch ON.
(c) Inspect the voltage at the center of each heat wire, as
shown.
VoltageCriteria
Approx. 5VOkay (No break in wire)
Approx. 10V or 0VBroken wire
HINT:
If there is approximately 10 V, the wire is broken between the
center of the wire and the positive (+) end. If there is no voltage,
the wire is broken between the center of the wire and ground.
(d) Place the voltmeter positive (+) lead against the defogger
wire on the battery side.
(e) Place the voltmeter negative (±) lead with the foil strip
against the wire on the ground side.
(f) Slide the positive (+) lead from battery to ground side.
(g) The point where the voltmeter deflects from several V to
zero V is the place where the defogger wire is broken.
HINT:
If the heat wire is not broken, the voltmeter indicates 0 V at the
positive (+) end of the heat wire but gradually increases to about
12 V as the meter probe moves to the other end.
Page 154 of 1111

I04123
I04119
2
3
I01200
2 1
35
2 5
1 3
I05474
1
2
BE±120
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
2421 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSPECT POWER WINDOW SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
AUTO3 ± 5Continuity
UP3 ± 6Continuity
OFF±No continuity
DOWN3 ± 4Continuity
If continuity is not as specified, replace the switch.
7. INSPECT POWER WINDOW SWITCH CIRCUIT
Passenger side: (See page DI±908)
Rear LH side: (See page DI±936)
Rear RH side: (See page DI±953)
8. INSPECT POWER WINDOW SWITCH ILLUMINATION
Connect the positive (+) lead from the battery to terminal 3 and
the negative (±) lead to terminal 2, and check that the indicator
light lights up.
If operation is not as specified, replace the switch.
9. INSPECT POWER MAIN RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
10. INSPECT POWER MAIN RELAY CIRCUIT
(See page BE±21)
11. Driver 's door:
INSPECT POWER WINDOW MOTOR OPERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2, and check that
the motor turns clockwise.
Page 174 of 1111
BE0GQ±03
I01365
Luggage Compartment
Courtesy SwitchIgnition Switch
Door Lock Assembly
Door Lock Motor
Door Unlock Detection
Switch
Door Key Lock and
Unlock Switch
Door Lock Assembly
Door Lock Motor
Door Unlock Detection
Switch
Door Key Lock and Unlock SwitchLuggage Compartment
Opener Switch
Luggage Compartment
Key Lock and Unlock
Switch
Horn Theft Deterrent HornEngine Room No.1 Junction Block
HORN Fuse
Headlight Control Relay
Starter Relay
Engine Hood Courtesy Switch
Driver Side Junction Block
ST Fuse
Taillight Control RelayEngine Room No.2 Relay Block
Horn Relay
BE±140
± BODY ELECTRICALTHEFT DETERRENT SYSTEM
2441 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
THEFT DETERRENT SYSTEM
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.
Page 195 of 1111
BE0H5±06
I01348
Engine Room No.1
Junction BlockEngine Room No.2
Relay Block
Driver Side Junction BlockEngine Room No.3
Relay Block
Passenger Side Junction Block
BE±16
± BODY ELECTRICALPOWER SOURCE
2317 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
POWER SOURCE
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.
Page 196 of 1111
I04026
Engine Room No.1 Junction Block
Fuses Relays
1. MAIN H±Fuse
2. FL ABS NO.1 H±Fuse
3. ALT H±Fuse
4. ABS NO.2 H±Fuse
5. H±LP CLN H±Fuse
6. RAD NO.1 Fuse
7. ALT±S Fuse
8. EFI Fuse
9. TURN HAZ Fuse
10. TEL Fuse
11. AM2 Fuse
13. HORN Fuse 12. ETCS Fuse
14. MPX±B Fuse
15. ECU±B1 Fuse
16. HTR FuseB. Starter Relay A. Headlight Control Relay
C. EFI Relay
17. FAN MAIN H±Fuse
18. CDS FAN H±Fuse
20. H±LP R LWR Fuse 19. RAD FAN H±Fuse
21. H±LP L LWR Fuse
22. H±LP R UPR Fuse
23. H±LP L UPR Fuse1
2 3 4 5 6 7 8 9 10 11 12 13
14 15
16 18 17 19
20 21 22 23 A
BC
± BODY ELECTRICALPOWER SOURCE
BE±17
2318 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)