753 / 1006
HVAC
27
2. NOISE WHILE OPERATING A/C SYSTEM
TROUBLESHOOTING HINTS:
Magnetic clutch operation noise-Step 4
A/C compressor vane noise -Step 5-13.
A/C compressor slippage noise -Step 14-17.
Hose or refrigerant line interference noise -Step 18.
Step
Inspection
Action
1
Inspect a/c compressor vane
noise
Is there a jingling, popping, beep-
ing, or buzzing sound (A/C
compressor vane noise)?
Yes
Go to Step 5.
No
Go to next step.
2
Inspect a/c compressor slippage
noise
Is there a squeaking or whirling
sound (A/C compressor slippage
noise)?
Yes
Go to Step 14.
No
Go to next step.
3
Inspect a/c compressor interfer-
ence noise
Is there a ratting or vibrating
sound (Interference noise)?
Yes
Go to Step 18.
No
Go to next step.
4
Inspect magnetic clutch operation
noise
Is there clicking sound (Magnetic
clutch operation noise)?
Yes
Adjust clearance between pressure plate of
magnetic clutch and A/C compressor pulley, then
go to Step 19.
No
Condition is normal. (Recheck malfunction symp-
toms.)
5
Inspect a/c compressor noise time
Is noise heard continuously for
more than 3 seconds after A/C
compressor comes on?
Yes
Go to next step,
No
Condition is normal. (Noise occurs for 2-3 sec-
onds immediately after A/C compressor turns
on.)
6
Inspect idle speed Is it okay?
Yes
Go to next step.
No
Adjust idle speed, then go to Step 19.
7
Inspect refrigerant amount
Inspect refrigerant amount. See
refrigerant system service proce-
dures, refrigerant charge check
Is it okay?
Yes
Go to Step 10.
No
Go to next step.