Mazda CX-7 2007 Workshop Manual page 1141

STEP
13* INSPECT TO SEE WHETHER MALFUNCTION
IS IN MAGNETIC CLUTCH OR ELSEWHERE
• Test voltage at the following terminal of
magnetic clutch thermal protector.
— Terminal A (magnetic clutch operation
signal)
• Is voltage approx. 12 V?
14 INSPECT FUSE
• Are A/C relay power supply fuses okay?
15 INSPECT WIRING HARNESS BETWEEN
FUSE BLOCK AND A/C RELAY FOR LACK
OF CONTINUITY
• Test voltages at following terminals of A/C
relay.
— Terminal A (A/C relay control signal)
— Terminal C (A/C control signal)
• Are voltages approx. 12 V?
16 INSPECT TO SEE WHETHER MALFUNCTION
IS IN A/C RELAY OR WIRING HARNESS
(BETWEEN A/C RELAY AND MAGNETIC
CLUTCH) AND EVAPORATOR
TEMPERATURE SENSOR
• Test voltage at the following terminal of A/C
relay.
— Terminal D (magnetic clutch operation
signal)
• Is voltage approx. 12 V?
17 INSPECT EVAPORATOR TEMPERATURE
SENSOR
• Inspect evaporator temperature sensor.
• Is it okay?
18 CONFIRM THAT MALFUNCTION SYMPTOMS
DO NOT RECUR AFTER REPAIR
• Does cool air blow out? (Are the results of
refrigerant system performance test okay?)
End Of Sie
NO.9 NOISE WHILE OPERATING A/C SYSTEM
9 Noise while operating A/C system.
• Noise from magnetic clutch, A/C compressor, hose or refrigerant line.
DESCRIPTION
• Magnetic clutch operation noise
• A/C compressor vane noise
POSSIBLE
• A/C compressor slippage noise
CAUSE
• Hose or refrigerant line interference noise
Diagnostic procedure
STEP
1 CHECK A/C COMPRESSOR VANE NOISE
• Is there a jingling, popping, beeping, or
buzzing sound (A/C compressor vane
noise)?
2 INSPECT A/C COMPRESSOR SLIPPAGE
NOISE
• Is there a squeaking or whirling sound (A/C
compressor slippage noise)?
3 INSPECT A/C COMPRESSOR
INTERFERENCE NOISE
• Is there a rattling or vibrating sound
(interference noise)?
4 INSPECT MAGNETIC CLUTCH OPERATION
NOISE
• Is there a clicking sound (magnetic clutch
operation noise)?
SYMPTOM TROUBLESHOOTING
INSPECTION
INSPECTION
Yes Inspect magnetic clutch, then go to Step 18.
No Go to the next step.
Yes Go to the next step.
No Replace fuse, then go to Step 18. If fuse burns out
immediately, go to the next step.
Yes Go to the next step.
No Repair wiring harness between fuse block and A/C relay,
then go to Step 18.
Yes Inspect wiring harness between A/C relay and magnetic
clutch.
• If above wiring harness is OK, go to the next step.
• If above wiring harness malfunctions, repair wiring
harness, then go to Step 18.
No Replace A/C relay, then go to Step 18.
Yes Go to the next step.
No Replace evaporator temperature sensor, then go to the next
step.
Yes Troubleshooting completed. Explain repairs to customer.
No Recheck malfunction symptoms, then repeat from Step 1 if
malfunction recurs.
Yes Go to Step 5.
No Go to the next step.
Yes Go to Step 14.
No Go to the next step.
Yes Go to Step 18.
No Go to the next step.
Yes Adjust clearance between pressure plate of magnetic clutch
and A/C compressor pulley, then go to Step 19.
(See 07-40-6 MAGNETIC CLUTCH ADJUSTMENT.)
No Condition is normal. (Recheck malfunction symptoms.)
ACTION
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ACTION
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