Page 17 of 3115
I24787
Front Heater Unit
Heater Radiator
Air Mix Servomotor
Air Outlet Servomotor Solar Sensor
Front Cooling Unit
Expansion Valve
Evaporator
Evaporator Temperature Sensor Rear Heater Unit
Blower Motor
Power Transistor
Heater Radiator
Air Mix Servomotor
Air Inlet Temperature Sensor
Room Temperature Sensor
(for Rear A/C)
Rear Cooling Unit
Blower Motor
Power Transister
Evaporator
Thermistor
Expansion Valve with Magnetic Valve
Blower Unit
Blower Motor
Blower Motor Control Rela
y
Air Inlet ServomotorA/C Amplifier
Integration Control Panel Room Temperature Sensor
(for Front A/C)
Rear A/C Control Switchw/ EMV:
w/o EMV:
A/C Control
A/C Amplifier
Cowl Side J/B LH
ACC Fuse
Cowl Side J/B RH
RR A/C AC-14
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
2739 Author: Date:
2004 LAND CRUISER (RM1071U)
Page 18 of 3115

AC1HL-05
I06757
Sight Glass
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-3
2728 Author: Date:
2004 LAND CRUISER (RM1071U)
ON-VEHICLE INSPECTION
1. INSPECT REFRIGERANT VOLUME
Observe the sight glass on the liquid tube.
Test conditions:
Engine speed at 1,500 rpm
Fan speed selector at ºHIº position
A/C switch ON
Temperature control dial at ºCOOLº position
Doors fully opened
ItemSymptomAmount of refrigerantRemedy
1Bubbles appear in sight glassInsufficient*
(1) Check for gas leakage with gas leak de-
tector and repair, if necessary
(2) Add refrigerant until bubbles disappear
2No bubbles appear in sight glassNone, sufficient or too muchRefer to item 3 and 4
3No temperature difference between com-
pressor inlet and outletEmpty or nearly empty
(1) Check for gas leakage with gas leak de-
tector and repair, if necessary
(2) Add refrigerant until bubbles disappear
4Temperature between compressor inlet and
outlet is noticeably differentCorrect or too muchRefer to items 5 and 6
5
Immediately after air conditioning system is
turned off, refrigerant in sight glass stays
clear
Too much
(1) Discharge refrigerant
(2) Evacuate air and charge proper amount
of purified refrigerant
6When air conditioning system is turned off,
refrigerant foams and then stays clearCorrect-
*: Bubbles in the sight glass with ambient temperatures higher than usual can be considered normal if cooling
is sufficient.
Page 19 of 3115
I01386
AC-4
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
2729 Author: Date:
2004 LAND CRUISER (RM1071U)
2. INSPECT REFRIGERANT PRESSURE WITH MAN-
IFOLD GAUGE SET
Check the trouble area using a set of manifold gauge set. Read
the manifold gauge pressure when following conditions are de-
tected.
Test conditions:
Temperature at the air inlet with the switch set
at RECIRC is 30 - 35 °C (86 - 95 °F)
Engine running at 2,000 rpm
Fan speed selector at ºHIº position
Temperature control dial on ºCOOLº position
HINT:
It should be noted that the gauge indications may vary depend-
ing on ambient temperature conditions.
(1) Normally functioning refrigeration system.
Gauge reading:
Low pressure side:
0.15 - 0.25 MPa (1.5 - 2.5 kgf/cm
2)
High pressure side:
1.37 - 1.57 MPa (14 - 15 kgf/cm
2)
Page 20 of 3115

I01387
Condition : Periodically cools and then fails to cool
I01388
Condition: Insufficient cooling
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-5
2730 Author: Date:
2004 LAND CRUISER (RM1071U)
(2) Moisture present in refrigeration system.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
During operation, pressure on low
pressure side sometimes become
a vacuum and sometime normal
Moisture entered in refrigeration
system freezes at expansion valve
orifice and temporarily stops cycle,
but normal state is restored after a
time when the ice melts Drier in over-saturated state
Moisture in refrigeration system
freezes at expansion valve orifice
and blocks circulation of refriger-
ant(1) Replace condenser
(2) Remove moisture in cycle
through repeatedly evacuating air
(3) Charge proper amount of new
refrigerant
(3) Insufficient cooling.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure low on both low and
high pressure sides
Bubbles seen in sight glass con-
tinuously
Insufficient cooling performance
Gas leakage at some place in re-
frigeration system Insufficient refrigerant in system
Refrigerant leaking
(1) Check for gas leakage with gas
leak detector and repair if neces-
sary
(2) Charge proper amount of re-
frigerant
(3) If indicated pressure value is
near 0 when connected to gauge,
create the vacuum after inspecting
and repairing the location of the
leak
Page 21 of 3115

I01389
Condition: Insufficient cooling
I01449
Condition: Does not cool (Cools from time to time in some cases) AC-6
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
2731 Author: Date:
2004 LAND CRUISER (RM1071U)
(4) Poor circulation of refrigerant.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure low in both low and
high pressure sides
Frost on tube from condenser to
unit
Refrigerant flow obstructed by dirt
in condensercondenser cloggedReplace condenser
(5) Refrigerant does not circulate.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Vacuum indicated on low pres-
sure side, very low pressure indi-
cated on high pressure side
Frost or dew seen on piping be-
fore and after condenser/ drier or
expansion valve Refrigerant flow obstructed by
moisture or dirt in refrigeration sys-
tem
Refrigerant flow obstructed by
gas leakage from expansion valve
Refrigerant does not circulate
(1) Check expansion valve
(2) Clean out dirt in expansion
valve by blowing with air
(3) Replace condenser
(4) Evacuate air and charge new
refrigerant to proper amount
(5) For gas leakage from expan-
sion valve, replace expansion
valve
Page 22 of 3115

I01390
Condition: Insufficient cooling
I01392
Condition: Insufficient cooling
NOTE : These gauge indica-
tions are shown when the
refrigeration system has
been opened and the refrig-
erant charged without vacu-
um purging.
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-7
2732 Author: Date:
2004 LAND CRUISER (RM1071U)
(6) Refrigerant overcharged or insufficient cooling of
condenser.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
No air bubbles seen through the
sight glass even when the engine
rpm is lowered Unable to develop sufficient per-
formance due to excessive refrig-
eration system
Insufficient cooling of condenser Excessive refrigerant in
cycle " refrigerant over charged
Condenser cooling " condenser
fins clogged or cooling fan faulty
(1) Clean condenser
(2) Check cooling fan with fluid
coupling operation
(3) If (1) and (2) are in normal
state, check amount of refrigerant,
and charge proper amount of re-
frigerant
(7) Air present in refrigeration system.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
The low pressure piping hot to
touch
Bubbles seen in sight glass
Air entered in refrigeration system
Air present in refrigeration sys-
tem
Insufficient vacuum purging
(1) Check compressor oil to see if
it is dirty or insufficient
(2) Evacuate air and charge new
refrigerant
Page 23 of 3115
I01450
Condition: Insufficient cooling
I01393
Condition : Does not cool AC-8
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
2733 Author: Date:
2004 LAND CRUISER (RM1071U)
(8) Expansion valve improperly.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
Frost or large amount of dew on
piping on low pressure side
Trouble in expansion valve
Excessive refrigerant in low
pressure piping
Expansion valve opened too
wide
Check expansion valve, and re-
place if defective
(9) Defective compression compressor.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on low and
high pressure sides
Pressure too low on high pres-
sure side
Internal leak in compressor
Compression defective
Valve leaking or broken sliding
parts
Repair or replace compressor
Page 24 of 3115

- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-9
2734 Author: Date:
2004 LAND CRUISER (RM1071U)
3. INSPECT IDLE-UP SPEED
(a) Warm up engine
(b) Inspect idle-up speed when following conditions are es-
tablished.
Test conditions:
Fan speed selector at ºHIº position
Temperature control dial at ºCOOLº position
A/C switch ON
Put gear shift in neutral
Magnetic clutch conditionIdle-up speed
Magnetic clutch not engaged700 ± 50 rpm
Magnetic clutch engaged780 ± 50 rpm
If idle speed is not as specified, check the idle control system.
4. INSPECT FOR LEAKAGE OF REFRIGERANT
(a) Stop engine.
(b) Secure good ventilation (The gas leak detector may not
react to volatile gases which are not refrigerant, such as
evaporated gasoline and exhaust gas)
(c) Repeat the test 2 or 3 times
(d) Make sure that there is some refrigerant remaining in the
refrigeration system.
When compressor is OFF: approx. 392 - 588 kPa (4 - 6
kgf´cm
2, 57 - 85 psi)
(e) Bring the gas leak detector close to the drain hose before
performing the test.
HINT:
After the blower motor stops, leave the cooling for more
than 15 minutes.
Expose the gas leak detector sensor under the drain
hose.
When bring the gas leak detector close to the drain hose,
make sure that the gas leak detector does not react to the
volatile gases.
If gas leaks are detected, lift up the vehicle.
(f) If gas leaks are not detected on the drain hose, remove
the blower resistor from the cooling unit. Then insert the
gas leak detector sensor into the unit to perform the test.
(g) Disconnect the connector and leave the pressure switch
for approx. 20 minutes. Then bring the gas leak detector
close to the pressure switch to perform the test.
(h) Bring the gas leak detector close to the refrigerant lines.