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Ignition Switch ºONº
Blower Switch º'ONº " Heater Relay ªONº (Blower Motor ºRUNº)
A/C Switch ºONº " A/C Amplifier º'ONº (A/C Amp. Main Power Supply) 1. PRINCIPLE OF A/C ELECTRICAL CIRCUIT
2. HOW IS MAGNETIC CLUTCH ENERGIZED?
The general process until the magnetic clutch is energized is shown below.
Dual Pressure Switch º'ONº:
Refrigerant Condition (2.1 kg/cm2 (30 psi, 206 kPa) less than 27 kg/cm
2 (384 psi, 2,648 kPa))
Thermistor supplies temperature signal of evaporator to A/C amplifier.
VSV ºONº " E/G Idle±Up
Magnetic Clutch Relay º'ONº
Temperature Sensor ºONº:
Temperature of Temperature Sensor is less than 180
°C (356°F).
Magnetic Clutch ºONº
Revolution Detecting Sensor supplies RPM signal of compressor to A/C amplifier.
If compressor is not locked, magnetic clutch is continuously energized.
± AIR CONDITIONING SYSTEMGeneral DescriptionAC±14
Page 216 of 2389

Blower does not, operate
(a) GAUGE fuse blown
(b) FL blown
(c) Circuit breaker faulty
(d) HEATER relay faulty
(e) HEATER fuse blown
(f) Blower motor faulty
(g) Blower resistor faulty
(h) Blower switch faulty
(i) Wiring or ground faulty
Magnetic clutch does not engage
(a) FL (30A CDS) blown
(b) Magnetic clutch relay faulty
(c) Magnetic clutch faulty
(d) A/C fuse faulty
(e) A/C switch faulty
(f) Thermistor faulty
(g) A/C amplifier faulty
(h) Revolution detecting sensor faulty
(i) Pressure switch faulty
(j) Wiring or ground faulty
(k) Refrigerant empty
Compressor does not rotate properly
(a) Drive belt loose or broken
(b) Compressor faulty
Expansion valve faulty
Leak i n systemReplace FL and check for short
Check relay
Check magnetic clutch
Replace fuse and check for short
Check switch
Check thermistor
Check amplifier
Check sensor
Check switch
Repair as necessary
Check refrigerant pressure Replace fuse and check for short
Replace FL and check for short
Check circuit breaker
Check relay .
Replace fuse and check for short
Check blower motor
Check blower resistor
Check blower switch
Repair as necessary
Magnetic clutch slipping
Expansion valve faulty
Excessive moisture in the system
Revolution detecting sensor faulty
A/C amplifier faulty
Wiring connection faulty
Condenser clogged
Drive belt slipping
Compressor faulty
Insufficient or too much refrigerant
Air i n systemCheck magnetic clutch
Check expansion valve
Evacuate and charge system
Check sensor
Check amplifier
Repair as necessary
Check condenser
Check or replace drive belt
Check compressor
Check refrigerant volume
Evacuate and charge systemAC±4 to 11
AC±37
AC±23
AC±4 to 11
AC±44
AC±43
AC±45 to 47
AC±24
AC±36
AC±4 to 11
AC±18, 22
Ajust or replace drive belt
Check compressor
Check expansion valve
Test system for leaks
TROUBLESHOOTING
AC±4 to 11
AC±4 to 11
AC±4 to 11
BE±73
AC±4 to 11
Cool air comes out
only at high speedAC±24
AC±45 to 47
AC±4 to 11 Coo! air comes
out intermittently
BE±73
BE±72, 74
AC±4 to 11
AC±33
AC±21
AC±23
AC±22 AC±21
AC±23
AC±39
AC±42
* FL: Fusible LinkPossible cause
AC±23
AC±39 No coolingRemedy Problem
Page
± AIR CONDITIONING SYSTEMTroubleshootingAC±16
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RELAYS
INSPECTION OF A/C RELAY
1. REMOVE COVER OF RELAY BOX
2. REMOVE RELAY
3. INSPECT RELAY CONTINUITY
(Magnetic Clutch Relay)
If continuity is not as specified, replace the relay.
(A/C Fan Relay No. 3)If continuity is not as specified, replace the relay.
If continuity is not as specified, replace the
relay.
Apply battery voltage to
terminal 2 (±j and 6 (+)Apply battery voltage to
terminal 1 and 3
Apply battery ±voltage to
terminal 1 and 3
(A/C Fan Relay No. 2)
Condition
ConditionCondition
Terminal
Terminal
Terminal
Constant
ConstantConstant
± AIR CONDITIONING SYSTEMRelaysAC±37
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WATER TEMPERATURE SWITCH
All±Trae/4WD Model
INSPECT SWITCH CONTINUITY
Inspect the switch continuity.
If detective, replace the water temperature
switch.If continuity is not as specified, replace the
relay. All±Trac/4WD Model
(A/C Cut Relay)
Apply battery voltage to
terminal 1 and 2Terminals
Condition
Constant
± AIR CONDITIONING SYSTEMRelaysAC±38
Page 242 of 2389
WATER TEMPERATURE SWITCH
All±Trae/4WD Model
INSPECT SWITCH CONTINUITY
Inspect the switch continuity.
If detective, replace the water temperature
switch.If continuity is not as specified, replace the
relay. All±Trac/4WD Model
(A/C Cut Relay)
Apply battery voltage to
terminal 1 and 2Terminals
Condition
Constant
± AIR CONDITIONING SYSTEMWater Temperature SwitchAC±38
Page 244 of 2389
1. REMOVEL LOWER AND UPPER UNIT CASES
(a) Discoonnect connectors
(b) Remove wire harness.
(c) Remove four clips.
(d) Remove five screws.
(e) Remove condenser fan control amplifier (2vZ±FE
E/G) or A/C cut amplifier (3S±FE E/G).
(f) Remove compressor control amplifier (2VZ±FE
E/G) or
A/C cut relay (All±Trac/4WD model).
(g) Remove upper unit case.
(h) Remove thermistor with thermistor holder.
(i) Remove lower unit case.
2. REMOVE EXPANSION VALVE
(a) Disconnect the liquid tube from the inlet fitting of the
expansion valve.
(b) Remove the packing and heat sensing tube from
suction tube of evaporator.
DISASSEMBLY OF COOLING UNIT
± AIR CONDITIONING SYSTEMCooling UnitAC±40