TM 9-2320-387-24-2
Table 14-3. Air Conditioning
Troubleshooting (Cont’d).
MALFUNCTION
TEST OR INSPECTION
I
4. UNUSUAL NOISE WITH CLUTCH ENGAGED
a. Inspect compressor mounting component.
Step 1.
Check for a loose belt.
Step 2.
Check for broken bracket or compressor mounting gear. Replace damaged components
(para. 25-20).
Step 3.
Check for missing, broken, or loose bolts at compressor and engine mounting points.
Replace damaged or missing components (para. 25-20).
Step 4.
Check for loose or wobbling compressor pulley and for shaft nut torque and bottoming.
Repair or replace damaged components (para. 25-20).
b. Inspect engine compartment.
Step 1.
Disconnect serpentine belt (para. 3-81) and operate engine at idle to isolate engine noise
from air conditioner compressor noise. If noise condition stops, continue to step 2. If noise
condition still exists, refer to mechanical troubleshooting (table 2-l).
Step 2.
Check for proper refrigerant charge (malfunction la). Low or excessive refrigerant charge
can cause unusual noise.
Step 3.
Check clutch air gap (space between pulley and front clutch plate) with feeler gauge. Gap
must be within range of 0.016 - 0.031 in. (0.406 - 0.787 mm>. If air gap is incorrect,
replace compressor (para. 25-20).
c. Check clutch and pulley bearing operation.
Step 1.
Remove serpentine belt (para. 3-81).
Step 2.
Rotate pulley by hand and listen for bearing noise while feeling for hard spots. If noise or
hard spots are excessive, replace compressor (para. 25-20).
d. Check oil level.
Insufficient amount of oil may cause compressor to be noisy. Restore oil to correct level (para. 25-15).
END OF TESTING!
5. UNUSUAL NOISE WITH CLUTCH DISENGAGED
.
a. Check clutch air gap (space between pulley and front clutch plate) with feeler gauge. Gap must be
within range of 0.016 - 0.031 in. (0.406 - 0.787 mm). If air gap is out of specification, replace
compressor (para. 25-20).
b. Check for defective clutch pulley. Replace compressor (para. 25-20).
END OF TESTING!
6. lNCORREClOl1 LEVEL OR LEAK
NOTE
There is no oil dipstick port on this A/C compressor. Oil quantity
can only be checked in compressor by removing and draining the
compressor.
After a system component has been replaced or there is reason to suspect an incorrect oil level or
leak, check system (para. 25-20).
END OF TESTING!
14-22
