Page 1433 of 1833
Gauge indicationRefrigerant cycleProbable causeCorrective action
Low-pressure side becomes
negative.
AC362A
Liquid tank or front/rear side of
expansion valve's pipe is
frosted or dewed. High-pressure side is closed
and refrigerant does not flow.
"
Expansion valve or liquid tank
is frosted. After the system is left at rest,
start it again in order to con-
firm whether or not problem is
caused by water or foreign
particles.
I
If the problem is due to
water, drain water from
refrigerant or replace refrig-
erant.
I If it is due to foreign
particles, remove expansion
valve and remove them with
dry and compressed air.
I If either of the above meth-
ods cannot correct the
problem, replace expansion
valve.
I Replace liquid tank.
I Check compressor oil for
contamination.
DIAGNOSES Ð Overall System
Performance Test Diagnoses (Cont'd)
HA-36
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Page 1434 of 1833
Symptom Chart
DIAGNOSTIC TABLE
PROCEDUREPrelimi-
nary
Check Diagnostic
Procedure Main Power
Supply and
Ground Circuit Check Electrical Components Inspection
SYMPTOM
Preliminary check 1
Preliminary check 2
Diagnostic procedure 1
Diagnostic procedure 2
Diagnostic procedure 3
15A Fuses
10A Fuse
15A Fuse
Blower motor
Intake door motor
Resistor
A/C switch
Fan switch
A/C relay
Dual-pressure switch Compressor
Harness Magnet clutch
A/C does not blow cold air.q qqqq qqqqqqq
Blower motor does not rotate.
qqqqq q
Magnet clutch does not
engage when A/C switch and
fan switch are ON.
qq qqqqqq
Noise
Intake door does not change.qq q
,: The number indicates checking order.
q: Refer to each flow chart for checking order. (It depends on malfunctioning portion.)
TROUBLE DIAGNOSES
HA-37
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Page 1435 of 1833

Preliminary Check
PRELIMINARY CHECK 1
A/C does not blow cold air.
DOES AIR FLOW FROM VENTS?
Condition
IIgnition switch, A/C switch, and
fan switch are ON.
I Mode lever is in VENT mode
and temperature lever is in full
cold position.
OK
ENG
IS BLOWER MOTOR OPERAT-
ING NORMALLY?
Ye s N o
CHECK
BLOWER
MOTOR
OPERATION.
Go to Diagnos-
tic Procedure
1.
CHECK COMPRESSOR BELT TEN-
SION.
Refer to MA section.
NG OK
FNG
CHECK COMPRESSOR OPERA-
TION.
OK CHECK FOR EVAPORATOR COIL
FREEZE UP.
Remove intake unit. Check if
evaporator freezes.
NG
(Freezes up)
OK
(Does not
freeze up)
Adjust or
replace com-
pressor belt.
CHECK REFRIGERATION CYCLE
PRESSURE WITH RECOVERY/
RECYCLING EQUIPMENT CON-
NECTED.
Refer to Performance Chart,
HA-31.
NG OK CHECK VENTI-
LATOR DUCT
FOR AIR
LEAKS.
CHECK AMOUNT OF
REFRIGERANT.
Check amount of refrigerant using
ACR4 (Refrigerant recovery &
recharging equipment).
OK
NGGo to
Perfor-
mance Test
Diagnoses.
CHECK THERMO CONTROL
AMP. OPERATION.
Refer to Electrical Components
Inspection, HA-62.
Evacuate sys-
tem and
recharge with
refrigerant.CHECK FOR
REFRIGERANT
LEAKS.
Go to Diagnostic Procedures 2.
CHECK AIR CONTROL CABLE
ADJUSTMENT.
Refer to Control Linkage
Adjustment, HA-64.FOK
CHECK EVAPORATOR OUTLET
AIR TEMPERATURE.
Refer to Performance Chart,
HA-31.
NG
CHECK THERMO CONTROL
AMP. OPERATION.
Refer to Electrical Components
Inspection, HA-62.
H
HH
HHH
HHH
HH
H
H
H
TROUBLE DIAGNOSES
HA-38
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Page 1436 of 1833
PRELIMINARY CHECK 2
Noise
Check where noise
comes from.
Expansion valveCompressorRefrigerant lineBelt
Replace expan-
sion valve.Replace com-
pressor.
The line is fixed directly
to the body.The line is not fixed.
Fix the line with rubber
or some vibration
absorbing material.Fix the line tightly.
The belt vibration is
intense.Side of belt is worn
out.
Readjust belt tension.
Refer to ENGINE MAIN-
TENANCE in MA sec-
tion.The pulley center
does not match.
Readjust the pulley
center.
HHHH
HH
HH
HH
HH
HH
TROUBLE DIAGNOSES
Preliminary Check (Cont'd)HA-39
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Page 1437 of 1833
Harness Layout for A/C System
LH DRIVE MODELS
RHA342I
TROUBLE DIAGNOSES
HA-40
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Page 1438 of 1833
RH DRIVE MODELS
RHA343I
TROUBLE DIAGNOSES
Harness Layout for A/C System (Cont'd)HA-41
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Page 1439 of 1833
Wiring Diagram Ð Heater
LHD MODELS
YHA400
TROUBLE DIAGNOSES
HA-42
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Page 1440 of 1833
RHD MODELS
YHA401
TROUBLE DIAGNOSES
Wiring Diagram Ð Heater (Cont'd)HA-43
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