1986 TOYOTA LAND CRUISER check engine

N13790
Low Pressure
Service Valve
High Pressure
Service Valve
I08298
Properly
Charged
Insufficiently
Charged
AC-12
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
2737 Author
: Date
:
2004 LAND CRUISER (RM1071U)
3. CHARGE REFRIGERANT INTO REFRIGERATION
SYSTEM
If there is no leak after refrigerant leak check, charge the proper
amount of refrigerant into the refrigeration system.
CAUTION:

Do not run the engine when charging the system
through the high pressure side.

Do not open the low pressure hand valve when the
system is being charged with liquid refrigerant.
(a) Open the high pressure hand valve fully.
(b) Charge specified amount of refrigerant, then close the
high pressure hand valve.
HINT:
No bubbles in the sight glass indicates that the system is fully
charged.
(c) Partially charge the refrigeration system with refrigerant.
(1) Start engine and race engine at 1,500 rpm.
(2) Set fan speed selector to ºHIº.
(3) Set temperature control to ºMAX. COOLº.
(4) Set air inlet control to ºRECIRCº.
(5) Fully open doors (Sliding roof: closed).
(6) Open the low pressure hand valve.
CAUTION:
Do not open the high pressure hand valve.
(d) Charge refrigerant until bubbles disappear and check the
pressure on the gauge through the sight glass.

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.

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)

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

- 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.

AC1IK-03
I068122
1
I06813
3
AC-60
- AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
2785 Author
: Date
:
2004 LAND CRUISER (RM1071U)
COMPRESSOR AND MAGNETIC
CLUTCH
ON-VEHICLE INSPECTION
1. INSPECT COMPRESSOR FOR METALLIC SOUND
Check there is abnormal metallic sound from the compressor
when the A/C switch is ON.
If abnormal metallic sound is heard, replace the compressor as-
sembly.
2. INSPECT REFRIGERANT PRESSURE
(See page AC-3)
3. INSPECT VISUALLY FOR LEAKAGE OF REFRIGER-
ANT
Using a gas leak detector, check for leakage of refrigerant.
If there is any leakage, replace the compressor assembly.
4. INSPECT COMPRESSOR LOCK SENSOR RESIS-
TANCE
(a) Disconnect the connector.
(b) Measure resistance between terminal 1 and 2.
Standard resistance:
570 - 1,050 W at 20°C (68 °F)
If resistance is not as specified, replace the compressor.
5. CHECK FOR LEAKAGE OF GREASE FROM CLUTCH
BEARING
6. CHECK FOR SIGNS OF OIL ON PRESSURE PLATE OR
ROTOR
7. INSPECT MAGNETIC CLUTCH BEARING FOR NOISE
(a) Start engine.
(b) Check for abnormal noise from the compressor when the
A/C switch is OFF.
If abnormal noise is being emitted, replace the rotor of magnetic
clutch.
8. INSPECT MAGNETIC CLUTCH OPERATION
(a) Disconnect the connector.
(b) Connect the positive (+) lead from the battery to terminal
3 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.

AC3OW-01
I25168
1
23
4
Z13470
Magnetic clutch control
Low Pressure Side
ON (Continuity)
196 kpa
(2.0 kgf/cm
2, 28 psi)
OFF (No Continuity)High Pressure Side
3,140 kpa
(32.0 kgf/cm2, 455 psi)
OFF (No Continuity)
- AIR CONDITIONINGPRESSURE SWITCH
AC-91
2816 Author
: Date
:
2004 LAND CRUISER (RM1071U)
PRESSURE SWITCH
ON-VEHICLE INSPECTION
1. SET VEHICLE IN THESE CONDITION
(a) Engine speed at 1,500 rpm
(b) Blower speed control switch at ºHIº position
(c) Temperature control dial at ºMAX. COOLº position
(d) Manifold gauge set setting
2. INSPECT PRESSURE SWITCH OPERATION
(a) Disconnect the connector.
(b) Inspect pressure switch continuity (Magnetic Clutch Con-
trol)
(1) Connect the positive (+) lead from the ohmmeter to
terminal 1 and the negative (-) lead to terminal 2.
(2) Check continuity between terminals when the re-
frigerant pressure is changed, as shown in the il-
lustration.
If continuity is not as specified, replace the pressure switch.

AC1KA-04
I06684
43
W
I06685
1 2
I06686
- AIR CONDITIONINGREAR COOLING UNIT
AC-29
2754 Author
: Date
:
2004 LAND CRUISER (RM1071U)
REAR COOLING UNIT
ON-VEHICLE INSPECTION
1. INSPECT EXPANSION VALVE
(a) Check amount of gas during refrigeration cycle.
(b) Set on manifold gauge set.
(c) Start the engine.
(d) Operate the A/C system.
(e) Inspect the expansion valve.
(1) Run the engine at 1,500 rpm for at least 5 minutes.
(2) Check the high pressure reading is 1.37 - 1.57 MPa
(14 - 16 kgf/cm
2, 199 - 288 psi).
(3) Check the low pressure reading.
If the low pressure reading is 0 kPa (0 kgf/cm
2, 0psi), replace
the expansion valve.
2. REMOVE REAR DOOR SCUFF PLATE RH
3. REMOVE REAR FLOOR MAT SUPPORT PLATE
4. REMOVE QUARTER TRIM PANEL RH
5. INSPECT THERMISTOR RESISTANCE
(a) Disconnect the connector.
(b) Measure resistance between terminal 3 and 4.
Standard resistance: Approx. 1.5 kW at 25 °C (77 °F)
If resistance is not as specified, proceed ºINSPECTIONº on
page AC-36.
6. INSPECT MAGNETIC VALVE CONTINUITY
(a) Disconnect the connector.
(b) Check the continuity exists between terminal 1 and 2.
If resistance is not as specified, proceed ºINSPECTIONº on
page AC-36.
7. CHECK FOR LEAKAGE OF REFRIGERANT
(a) Remove the power transistor.
(b) Using a gas leak detector, check for leaks of refrigerant.
If there is a leakage, check the evaporator or tightening torque
at the joints.