300Tdi Discovery
82
AIR CONDITIONING
4
FAULT DIAGNOSIS
FAULT
CAUSE
REMEDY
E.
NOISY
EXPANSION
VALVE
(steady hissing)
1. Low refrigerant charge; evident by
bubbles in sight glass.
1. Leak test. Repair or replace
components as required.
F.
1. Expansion valve not operating
1. Refer to C-2, C-3, D-1
INSUFFICIENT
properly.
and E.
COOLING
2. Low refrigerant charge-evident
2. Refer to B-1 and E.
by bubbles in sight glass.
3. Compressor not pumping.
3. Refer to B-2 and B-3
G.
1. Belt tension.
1. Adjust belt tension.
COMPRESSOR
2. Excessive head pressure.
2. Refer to A-1 through
BELT
A-4 and C-6.
SLIPPING
3. Incorrect alignment of pulleys
3. Repair as needed.
or worn belt not riding properly.
4. Nicked or broken pulley.
4. Replace as needed.
5. Seized compressor.
5. Replace compressor.
1. Loose or missing mounting bolts.
1. Repair as necessary.
2. Broken mounting bracket.
2. Replace bracket.
3. Loose flywheel or clutch
3. Repair as necessary.
retaining bolt.
H.
4. Rough idler pulley bearing.
4. Replace bearing.
ENGINE
5. Bent, loose, or improperly
5. Repair as necessary.
NOISE
mounted engine drive pulley.
AND/OR
6. Defective compressor bearing.
6. Replace bearing.
VIBRATION
7. Insecure mountings of
7. Repair as necessary.
accessories; generator, power
steering, air filter, etc.
8. Excessive head pressure.
8. Refer to A-1, A-2, A-3
A-4 and C-6.
9. Incorrect compressor oil level.
9. Refer to compressor Oil
Level Check.
HEATER AND AIR CONDITIONING - CIRCUIT
DIAGRAMS
1. For details of heating and air conditioning
electrics
See Electrical Trouble Shooting
Manual.
