Page 1449 of 1833
Main Power Supply and Ground Circuit Check
POWER SUPPLY CIRCUIT CHECK FOR A/C SYSTEM
Check power supply circuit for air conditioning system.
Refer to ªPOWER SUPPLY ROUTINGº in EL section and ªWir-
ing Diagramº.
TROUBLE DIAGNOSES
HA-52
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Page 1450 of 1833

Diagnostic Procedure 1
SYMPTOM: Blower motor does not rotate.
IPerform PRELIMINARY CHECK 2 before referring to the
following flow chart.
Check if blower motor rotates properly at
each fan speed.
Conduct check as per flow chart at left.234EqB5EqC
(Go to next page.)
1
CHECK POWER SUPPLY FOR BLOWER
MOTOR.
I
Disconnect blower motor harness con-
nector.
I Turn ignition switch to ACC or ON posi-
tion.
Do approx. 12 volts exist between blower
motor harness terminal No. q
1and body
ground?
OK
ENG Check 15A fuses at fuse
block.
(Refer to ªPOWER SUP-
PLY ROUTINGº in EL sec-
tion and ªWiring Diagramº.)
IPut fan switch to ON position.
Check circuit continuity between blower
motor harness terminal No. q
2and body
ground.
OK
ENG Reconnect blower motor
harness connector.
CHECK BLOWER MOTOR.
(Refer to Electrical Components
Inspection, HA-61.)
NG
Replace blower motor.
CHECK BLOWER MOTOR CIRCUIT
BETWEEN BLOWER MOTOR AND
RESISTOR.
I Put fan switch to OFF position.
Do approx. 12 volts exist between resistor
harness terminal No. q
1and body ground?
OK
ENG
Disconnect blower motor
and resistor harness con-
nectors.
Note
I Turn ignition switch OFF.
Check circuit continuity
between blower motor har-
ness terminal No. q
2and
resistor harness terminal
No. q
1.
qA
(Go to next page.)Note:
If the result is NG after checking circuit continuity, repair har-
ness or connector.
INCIDENT Flow chart
No.
1 Fan fails to rotate.
1
2 Fan does not rotate at
1-speed.2
3Fan does not rotate at
2-speed.3
4Fan does not rotate at
3-speed.4
5Fan does not rotate at
4-speed.5
YHA408
YHA409
YHA410
YHA411
H
H
H
H
H
H
TROUBLE DIAGNOSES
HA-53
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Page 1451 of 1833
qA
1
qB
234
qC
5
H
CHECK RESISTOR AFTER DISCONNECT-
ING IT.
(Refer to Electrical Components Inspection,
HA-61.)
OK
H
NG
Replace resistor.
Reconnect resistor harness connector.
1
H
234
CHECK FAN SWITCH CIRCUIT.
Do approx. 12 volts exist between each fan switch har-
ness terminal and body ground?
NG
H
OK
2
3
4
5
Note
Check circuit continuity between
fan switch and resistor (or blower
motor).
CHECK FAN SWITCH AFTER DISCON-
NECTING IT.
(Refer to Electrical Components Inspection,
HA-61.)
OK
ENG Replace fan switch.
Note
Check circuit continuity between fan switch
harness terminal No. q
1and body ground.
OK
Replace blower motor.
Note:
If the result is NG after checking circuit continuity, repair har-
ness or connector.
Flow
chart No. Terminal No. Voltage
!@
q2
Body
ground Approx.
12Vq3
q4
q5
YHA412
YHA413
RHA344I
H
H
H
H
H
H
H
TROUBLE DIAGNOSES
Diagnostic Procedure 1 (Cont'd)
HA-54
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Page 1452 of 1833
Diagnostic Procedure 2
SYMPTOM: Magnet clutch does not engage when A/Cswitch and fan switch are ON.
IPerform PRELIMINARY CHECK 1 before referring to the
following flow chart.
CHECK POWER SUPPLY FOR COM-
PRESSOR.
Disconnect compressor harness connec-
tor.
ITurn ignition switch ON and A/C switch
ON.
Do approx. 12 volts exist between com-
pressor harness terminal No. q
1and
body ground?
OK
ENG CHECK A/C RELAY
OPERATION.
Do approx. 12 volts exist
between A/C relay harness
terminal No. q
5and body
ground.
OK NG
Check magnet clutch coil.
OK q
AqB
Replace magnet clutch.
Refer to COMPRESSOR Ð Model DKS-
17CH (ZEXEL make).
Note:
If the result is NG after checking circuit continuity, repair harness or connec-
tor.
YHA415
RHA345I
HHH
H
TROUBLE DIAGNOSES
HA-55
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Page 1453 of 1833

qAqB
ITurn ignition switch OFF.
Disconnect A/C relay harness connec-
tor.CHECK POWER SUPPLY
FOR A/C RELAY.
Disconnect A/C relay.
Do approx. 12 volts exist
between A/C relay harness
connector terminal No.
q
3and body ground?
NG
OK
Note
Check circuit continuity between A/C
relay harness connector terminal No.
q
5and compressor harness connector
terminal No. q
1.
If NG, check harness connectors.
H
CHECK POWER SUPPLY
CIRCUIT AND 10A FUSE AT
FUSE BLOCK.
(Refer to ªPOWER SUPPLY
ROUTINGº in EL section and
Wiring Diagram.)
I Turn ignition switch ON.
CHECK POWER SUPPLY FOR A/C
RELAY (Coil side).
Do approx. 12 volts exist between A/C
relay harness connector terminal No.
q
2and body ground?
H
ENG CHECK POWER SUPPLY
FOR A/C CONTROL PANEL.
Disconnect A/C control panel
harness connector.
Do approx. 12 volts exist
between A/C control panel
harness connector terminal
No.q
1and body ground?
NG
OKFqC
(Go to next page.)
CHECK POWER SUPPLY
CIRCUIT AND 10A FUSE AT
FUSE BLOCK.
(Refer to ªPOWER SUPPLY
ROUTINGº in EL section and
Wiring Diagram.)
Note:
If the result is NG after checking circuit continuity, repair harness or connec-
tor.
YHA417
YHA418
YHA419
YHA420
HH
H
H
H
H
TROUBLE DIAGNOSES
Diagnostic Procedure 2 (Cont'd)
HA-56
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Page 1454 of 1833

qC
CHECK A/C RELAY AFTER DISCON-
NECTING IT.
(Refer to Electrical Components
Inspection, HA-62.)
OK
ENGReplace A/C relay.
Reconnect A/C relay.
Note
CHECK COIL SIDE CIRCUIT OF A/C
RELAY.
Do approx. 12 volts exist between
ECM harness connector terminal No.
204(TD27Ti models) or q15(ZD30DDTi
models) and body ground?
OK
ENG ITurn ignition switch OFF.
Check circuit continuity
between A/C relay harness
terminal No. q
1and ECM
harness connector terminal
No.
204(TD27Ti models)
or q
15(ZD30DDTi models).
CHECK VOLTAGE FOR THERMO
CONTROL AMP.
Do more than 8 volts exist between
thermo-control amp. harness connector
terminal No. q
2and body ground?
OK
ENG
ITurn ignition switch OFF.
Check circuit continuity
between thermo-control
amp. harness connector
terminal No. q
2and dual-
pressure switch connector
terminal No. q
2.
OK
q
D
(Go to next page.) CHECK DUAL-PRES-
SURE SWITCH.
(Refer to Electrical Compo-
nents Inspection, HA-62.)
NGOK
q
E
(Go to page HA-59.) Replace dual-pressure
switch.
Note:
If the result is NG after checking circuit continuity, repair harness or connec-
tor.
YHA421
YHA422
YHA423
YHA424
H
H
H
H
HH
HH
TROUBLE DIAGNOSES
Diagnostic Procedure 2 (Cont'd)
HA-57
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Page 1455 of 1833

qD
CHECK POWER SUPPLY FOR
THERMO-CONTROL AMP.
Disconnect thermo-control amp. connec-
tor.
Do approx. 12 volts exist between thermo-
control amp. harness connector terminal
No.q
1and body ground?
OK
ENG
CHECK POWER SUPPLY
CIRCUIT AND 10A FUSE
AT FUSE BLOCK.
(Refer to ªPOWER SUP-
PLY ROUTINGº in EL sec-
tion and Wiring Diagram.)
ITurn ignition switch OFF.
CHECK BODY GROUND CIRCUIT FOR
THERMO-CONTROL AMP.
Disconnect thermo-control amp. harness
connector.
Ensure A/C switch is in ON position.
Ensure fan switch is in ON position
(1 to 4).
Does continuity exist between thermo
control amp. harness connector terminal
No. q
3and body ground?
OK
ENG
Disconnect fan switch har-
ness connector.
Ensure A/C switch is in ON
position.
OK
Note
Check circuit continuity
between thermo-control
amp. harness connector
terminal No. q
3and fan
switch harness connector
terminal No. q
6.
NG
Replace thermo-control amp.
Check A/C switch (Refer to
Electrical Components
Inspection, HA-61.)
OK
H Repair harness or connec-
tors.Note
CHECK BODY GROUND CIRCUIT FOR
FAN SWITCH.
Does continuity exist between fan switch
harness connector terminal
No. q
1and body ground?
OK
CHECK FAN SWITCH.
(Refer to Electrical Components
Inspection, HA-61.)
NG
Replace fan switch.
Note:
If the result is NG after checking circuit continuity, repair harness or connec-
tor.
YHA406
YHA425
YHA426
YHA427
H
H
H
HH
H
H
H
TROUBLE DIAGNOSES
Diagnostic Procedure 2 (Cont'd)
HA-58
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Page 1456 of 1833
qE
Note
Check circuit continuity between ECM
harness connector terminal No. q
21
(ZD30DDTi) or403(TD27Ti) and dual-
pressure switch harness connector termi-
nal No. q
1.
OK
CHECK ECM.
(Refer to EF & EC section.)
Note:
If the result is NG after checking circuit continuity, repair harness or connec-
tor.
YHA428
H
H
TROUBLE DIAGNOSES
Diagnostic Procedure 2 (Cont'd)
HA-59
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