• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.
Diagnostic procedure
STEP
|
INSPECTION
|
ACTION
|
|
---|---|---|---|
1
|
INSPECT A/C 7.5 A FUSE
• Inspect A/C 7.5 A fuse.
• Is it normal?
|
Yes
|
Go to next step.
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No
|
Replace fuse, then go to Step 15. If fuse burns out immediately, go to next step.
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||
2
|
CHECK TO SEE WHETHER MALFUNCTION IS IN BLOWER UNIT OR ELSEWHERE
• Turn ignition switch to ON position.
• Recirculate air inside vehicle.
• Does fan in blower unit rotate smoothly?
|
Yes
|
Go to Step 4.
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No
|
Go to next step.
|
||
3
|
INSPECT BLOWER UNIT INTAKE VENT
• Is intake vent of blower unit clogged?
|
Yes
|
Remove obstruction, then go to Step 15.
|
No
|
Inspect if there are any obstruction in passage between blower unit to A/C unit, then go to Step 15.
|
||
4*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN BLOWER RELAY SYSTEM OR POWER TRANSISTOR SYSTEM
• Turn ignition switch to ON position.
• Test voltage at the following terminal of blower motor.
• Is voltage approx. 12 V?
|
Yes
|
Go to Step 8.
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No
|
Go to next step.
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||
5*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN FUSE BLOCK AND BLOWER RELAY) OR ELSEWHERE
• Test voltage at the following terminal of blower relay.
• Is voltage approx. 12 V?
|
Yes
|
Go to next step.
|
No
|
Repair wiring harness between blower relay and HEATER 40 A fuse, then go to Step 15.
|
||
6*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN BLOWER RELAY AND GROND) OR ELSEWHERE
• Test voltage at the following terminal of blower relay.
• Is voltage approx. 0 V?
|
Yes
|
Go to next step.
|
No
|
Repair wiring harness between blower relay and ground, then go to Step 15.
|
||
7*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN BLOWER RELAY AND BLOWER MOTOR) OR BLOWER RELAY
• Test voltage at the following terminal of blower relay.
• Is voltage approx. 12 V?
|
Yes
|
Repair wiring harness between blower relay and blower motor, then go to Step 15.
|
No
|
Replace blower relay, then go to Step 15.
|
||
8*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN BLOWER MOTOR OR ELSEWHERE
• Test voltage at the following terminal of blower motor.
• Is voltage approx. 12 V?
|
Yes
|
Go to next step.
|
No
|
Inspect blower motor, then go to Step 15. (See BLOWER MOTOR INSPECTION.)
|
||
9*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN BLOWER MOTOR AND POWER TRANSISTOR) OR ELSEWHERE
• Test voltage at the following terminal of power transistor.
• Is voltage approx. 12 V?
|
Yes
|
Go to next step.
|
No
|
Repair wiring harness between blower motor and power transistor, then go to Step 15.
|
||
10*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN POWER TRANSISTOR AND GROUND) OR ELSEWHERE
• Test voltage at the following terminal of power transistor.
• Is voltage approx. 0 V?
|
Yes
|
Go to next step.
|
No
|
Repair wiring harness between power transistor and ground, then go to Step 15.
|
||
11
|
INSPECT BLOWER UNIT
• Inspect fan in blower unit.
• Is voltage approx. 0 V?
|
Yes
|
Go to next step.
|
No
|
Remove obstruction, repair or replace fan and blower unit case, then go to Step 15.
|
||
12*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN POWER TRANSISTOR OR ELSEWHERE
• Disconnect power transistor connector.
• Test voltage at the following terminal of power transistor.
• Is voltage approx. 10 V?
|
Yes
|
Replace power transistor, then go to Step 15.
|
No
|
Go to next step.
|
||
13*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN POWER TRANSISTOR AND A/C AMPLIFIER) OR ELSEWHERE
• Turn ignition switch to LOCK position.
• Disconnect A/C amplifier connector.
• Inspect for continuity at the following terminals between power transistor and A/C amplifier.
• Is there continuity?
|
Yes
|
Go to next step.
|
No
|
Repair wiring harness between power transistor and A/C amplifier, then go to Step 15.
|
||
14*
|
CHECK TO SEE WHETHER MALFUNCTION IS IN A/C AMPLIFIER OR WIRING HARNESS (SHORT TO GROUND BETWEEN POWER TRANSISTOR AND A/C AMPLIFIER) OR ELSEWHERE
• Inspect for continuity at the following terminal between power transistor and ground.
• Is there continuity?
|
Yes
|
Repair wiring harness between power transistor and ground, then go to next step.
|
No
|
Replace A/C amplifier, then go to next step.
|
||
15
|
VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER REPAIR
• Is air discharged from vent?
|
Yes
|
Troubleshooting completed.
Explain repairs to customer.
|
No
|
Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.
|