1996 TOYOTA LAND CRUISER AC pressure switch

IN04Q−07
−
INTRODUCTION TERMS
IN−33
33
Author: Date:
1996 LAND CRUISER (RM451U)
TERMS
ABBREVIATIONS USED IN THIS MANUAL
AbbreviationsMeaning
ABSAnti−Lock Brake System
ACAlternating Current
ACCAccessory
ACISAcoustic Control Induction System
ACSDAutomatic Cold Start Device
A.D.D.Automatic Disconnecting Differential
A/FAir−Fuel Ratio
AHCActive Height Control Suspension
ALRAutomatic Locking Retractor
ALTAlternator
AMPAmplifier
ANTAntenna
APPROX.Approximately
A/TAutomatic Transmission (Transaxle)
AT FAutomatic Transmission Fluid
AUTOAutomatic
AUXAuxiliary
AV GAverage
AV SAdaptive Variable Suspension
BABrake Assist
BACSBoost Altitude Compensation System
BATBattery
BDCBottom Dead Center
B/LBi−Level
B/SBore−Stroke Ratio
BTDCBefore Top Dead Center
BVSVBimetallic Vacuum Switching V alve
Calif.California
CBCircuit Breaker
CCoCatalytic Converter For Oxidation
CDCompact Disc
CFCornering Force
CGCenter Of Gravity
CHChannel
COMB.Combination
CPECoupe
CPSCombustion Pressure Sensor
CPUCentral Processing Unit
CRSChild Restraint System
CTRCenter
C/VCheck Valve
CVControl Valve
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AC2QC−03
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
AC−3
1996 LAND CRUISER (RM451U)
PROBLEM SYMPTOMS TABLE
Use the table below to help you find the cause of the problem.The numbers i\
ndicate the priority of the likely
cause of the problem. Check each part in order. If necessary, replace these parts.
SymptomSuspect AreaSee page
No blower operation
4. HTR Fuse
5. Heater main relay
6. Blower motor
7. Blower resistor
8. Blower speed control switch
9. Wire harness−
AC−64
AC−52
AC−57
AC−69 −
No air temperature control
1. Engine coolant volume
2. A/C control assembly
3. Water valve−
AC−69
AC−49
No compressor operation
1. Refrigerant volume
2. A.C Fuse
3. Magnetic clutch
4. Compressor
5. Pressure switch
6. Heater main relay
7. Blower speed control switch
8. A/C switch
9. A/C amplifier
10.Thermistor
11. Wire harnessAC−5 −
AC−33
AC−33
AC−61
AC−64
AC−69
AC−69
AC−74
AC−60 −
Compressor operates intermitently
1. Refrigerant volume
2. Pressure switch
3. A/C amplifier
4. Thermistor
5. Wire harnessAC−5
AC−61
AC−74
AC−60 −
No cool air comes out
1. Refrigerant volume
2. Refrigerant pressure
3. Drive belt
4. Magnetic clutch
5. Compressor
6. Pressure switch
7. Thermistor
8. A/C switch
9. A/C amplifier
10.A/C control assembly
11. Wire harnessAC−5
AC−5
AC−15
AC−33
AC−33
AC−61
AC−60
AC−69
AC−74
AC−69 −
Cool air comes out only at high engine rpm
1. Refrigerant volume
2. Drive bel
3. Magnetic clutch
4. Compressor
5. Condenser
6. Receiver
7. Expansion valve
8. Evaporator
9. Thermistor
10.A/C amplifier
11. Wire harnessAC−5
AC−15
AC−33
AC−33
AC−42
AC−39
AC−47
AC−45
AC−60
AC−74 −
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AC−4
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
1996 LAND CRUISER (RM451U)
Insuf
ficient cooling
1. Refrigerant volume
2. Drive belt
3. Magnetic clutch
4. Compressor
5. Condenser
6. Receiver
7. Expansion valve
8. Evaporator
9. Refrigerant line
10.Pressure switch
11. A/C amplifier
12.A/C control assemblyAC−5
AC−15
AC−33
AC−33
AC−42
AC−39
AC−47
AC−45
AC−20
AC−61
AC−74
AC−69
No engine idle up when A/C switch ON
1. A/C amplifier
2. ECM
3. Wire harnessAC−74 −
−
No warm air comes out
1. Engine coolant volume
2. A/C control assembly
3. Water valve
4. Heater radiator−
AC−69
AC−49
AC−46
A/C indicator does not light up when mode lever at DEF. position
1. Defroster mode switch
2. A/C switch
3. Wire harnessAC−69
AC−69 −
Rear heater:
SymptomSuspect AreaSee page
No blower operation
1. RR HTR Fuse
2. Rear heater relay
3. Rear heater switch
4. Rear blower motor
5. Rear blower resistor−
AC−65
AC−77
AC−55
AC−58
No warm air come out1. Engine coolant volume
2. Rear heater radiator−
AC−46
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N14063
AC2QD−01
I01386
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
AC−5
1996 LAND CRUISER (RM451U)
ON−VEHICLE INSPECTION
1. INSPECT REFRIGERANT VOLUME
Observe the sight glass on the liquid tube.
Test conditions:
Running engine at 1,500 rpm
Blower speed control switch set at ”HI”
A/C switch ON
Temperature control set at ”MAX. COOL”
Fully open doors
ItemSymptomAmount of refrigerantRemedy
1Bubbles present in sight glassInsufficient*
1. Check for gas leakage with gas leak
tester and repair if necessary
2. Add refrigerant until bubbles disappear
2No bubbles present in sight glassNone, sufficient or too muchRefer to items 3 and 4
3No temperature difference between compressor inlet and outletEmpty or nearly empty
1. Check for gas leakage with gas leaktester 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
5Immediately after air conditioning is turnedoff, refrigerant in sight glass stays clearToo much
1. Discharge refrigerant
2. Evacuate air and charge proper amount of purified refrigerant
6When air conditioning 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.
2. INSPECT REFRIGERAT PRESSURE WITH MANIFOLD
GAUGE SET
This is a method in which the trouble is located by using a man-
ifold gauge set. Read the manifold gauge pressure when the
these conditions are established:
Test conditions:
Temperature at the air inlet with the switch set at RECIRC
is 30 − 35° C (86 − 95° F)
Engine running at 1,500 rpm
Blower speed control switch set at high
Temperature control set at max. cool
HINT:
It should be noted that the gauge indications may vary slightly
due to 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)
SightGlass
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AC−10
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
1996 LAND CRUISER (RM451U)
3. INSPECT IDLE−UP SPEED
(a) Warm up engine
(b) Inspect idle −up speed when the these conditions are es-
tablished:
Blower switch HI
Electrical load OFF
A/C switch ON
Put gear shift in neutral
Magnetic clutch conditionIdle speed
Magnetic clutch not engaged650 ± 50 rpm
Magnetic clutch engaged800 ± 50 rpm
If idle speed is not as specified, check the IAC valve and air in-
take system.
4. INSPECT FOR LEAKAGE OF REFRIGERANT
(a) Perform in these conditions:
Stop engine.
Secure good ventilation (If not, the gas leak detec-
tor may react to volatile gases which are not refrig-
erant, such as evaporated gasoline and exhaust
gas.)
Repeat the test 2 or 3 times.
Make sure that there is some refrigerant remaining
in the refrigeration system.
When compressor is OFF: approximately 392 − 588
KPa (4 − 6 kgf/cm
2, 57 − 35 psi)
(b) Bring the gas leak detector close to the drain hose before
performing the test.
HINT:
After the blower motor is stopped, leave the cooling unit
for more than 15 minutes.
Expose the gas leak detector sensor the 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 such reaction is unavoidable, the vehicle must be lifted up.
(c) If gas leak is not detected on the drain hose, remove the
power transistor from the cooling unit. Then insert the gas
leak detector sensor into the unit and perform the test.
(d) Disconnect the connector and leave the pressure switch for approximately 20 minutes. Then bring the gas leak de-
tector close to the pressure switch and perform the test.
(e) Bring the gas leak detector close to the refrigerant lines and perform the test.
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AC2QL−01
Z17947
Liquid TubePressure Switch
Suction Tube
Discharge Hose CondenserReceiver
Suction Hose
10 (100, 7)
N·m (kgf·cm, ft·lbf) : Specified torque
 Non− reusable part
5.4 (55, 48 in.·lbf)
10 (100, 7)
14 (140, 10)
10 (100, 7)
10 (100, 7)10 (100, 7)
−
AIR CONDITIONING REFRIGERANT LINE
AC−21
1996 LAND CRUISER (RM451U)
LOCATION
N14066
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AC2QN−01
AC−22
−
AIR CONDITIONING REFRIGERANT LINE
1996 LAND CRUISER (RM451U)
REPLACEMENT
1. DISCHARGE REFRIGERANT IN REFRIGERATION SYSTEM
2. REPLACE FAULTY TUBE OR HOSE
NOTICE:
Cap the open fittings immediately to keep moisture or dirt out of the sy\
stem.
3. TORQUE CONNECTIONS TO SPECIFIED TORQUE
NOTICE:
Connections should not be torqued tighter than the specified torque.
Part tightenedN·mkgf·cmft·lbf
Compressor x Discharge hose101007
Compressor x Suction hose101007
Condenser x Discharge hose101007
Condenser x Liquid tube101007
Reciever x Liquid tube5.45548 in.·lbf
Pressure switch x Liquid tube101007
Cooling unit x Liquid tube101007
Expansion valve x Evaporator5.45548 in.·lbf
Cooling unit x Suction tube101007
Liquid tube (Piping joint)1414010
Suction line (Block joint)101007
4. EVACUATE AIR IN REFRIGERATION SYSTEM AND CHARGE WITH REFRIGERANT
Specified amount: 850 ± 50 g (29.98 ± 1.76 oz.)
5. INSPECT FOR LEAKAGE OF REFRIGERANT
Using a gas leak detector, check for leakage of refrigerant.
If there is leakage, check the tightening torque at the joints.
6. INSPECT AIR CONDITIONING OPERATION
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AC2R5−01
N06158
−
AIR CONDITIONING COMPRESSOR AND MAGNETIC CLUTCH
AC−33
1360
Author: Date:
1996 LAND CRUISER (RM451U)
COMPRESSOR AND MAGNETIC
CLUTCH
ON−VEHICLE INSPECTION
1. INSTALL MANIFOLD GAUGE SET (See page AC−18 )
2. START ENGINE
Run the engine at 1,500 rpm.
3. INSPECT COMPRESSOR FOR METALLIC SOUND
Check if there is a metallic sound from the compressor when the
A/C switch is on.
If metallic sound is heard, replace the compressor assembly.
4. INSPECT REFRIGERANT PRESSURE (See page AC−5 )
5. STOP ENGINE
6. INSPECT VISUALLY FOR LEAKAGE OF REFRIGER- ANT FROM SAFETY SEAL
Using a gas leak detector, check for leakage of refrigerant.
If there is any leakage, replace the compressor assembly.
7. REMOVE MANIFOLD GAUGE SET (See page
AC−19 )
8. MAKE THESE VISUAL CHECKS:
(a) Leakage of grease from the clutch bearing.
(b) Signs of oil on the pressure plate or rotor. Repair or replace, as necessary.
9. INSPECT MAGNETIC CLUTCH BEARING FOR NOISE
(a) Start engine.
(b) Check for abnormal noise from near the compressor when the A/C switch is OFF.
If abnormal noise is being emitted, replace the magnetic clutch.
10. INSPECT MAGNETIC CLUTCH
(a) Disconnect the connector from the magnetic clutch.
(b) Connect the positive (+) lead from the battery to the termi-
nal on the magnetic clutch connector and the negative ( −)
lead to the body ground.
(c) Check that the magnetic clutch is energized.
If operation is not as specified, replace the magnetic clutch.
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