300Tdi Discovery
AIR CONDITIONING
1
FAULT DIAGNOSIS
AIR CONDITIONING FAULTS
FAULT
CAUSE
REMEDY
1. Incorrect voltage.
1. Check voltage.
A.
2. Open or defective fuse or relay.
2. Check and replace as necessary.
BLOWER
3. Loose wire connection including
3. Check system wires; tighten
MOTOR
ground.
all connections.
INOPERATIVE
4. Switch open or defective.
4. Replace switch.
OR SLOW
5. Tight, worn, or burnt motor
5. Replace motor.
RUNNING
bearings.
6. Open rotor windings.
6. Replace motor.
7. Worn motor brushes.
7. Replace motor.
8. Shaft binding-blade misaligned.
8. Check alignment. Repair or replace
as necessary.
9. Defective resistors
9. Rectify or replace.
1. Incorrect voltage.
1. Check voltage.
2. Open or defective fuse or relay.
2. Check and replace as necessary.
B.
3. Defective thermostat control or
3. Replace thermostat or
COMPRESSOR
pressure switch.
pressure switch.
CLUTCH
4. Shorted or open field coil.
4. Replace coil.
INOPERATIVE
5. Bearing seized (clutch will not
5. Replace clutch pulley assembly.
disengage).
6. Refrigeration circuit problem causing
heavy load and excessive drive
torque.
6. Check and rectify.
1. Incorrect alignment.
1. Check alignment; repair as
necessary.
2. Loose belt.
2. Adjust to proper tension.
C.
3. Compressor not mounted securely.
3. Repair as necessary.
COMPRESSOR
4. Bearing in clutch-pulley
4. Remove clutch and replace
CLUTCH
assembly not pressed in.
clutch pulley assembly.
NOISY
5. Low voltage to clutch.
5. Check connections and voltage.
6. Clutch will not spin freely.
6. Refer to B5 above.
7. Oil on clutch face.
7. Check compressor seals for leaks.
8. Slipping clutch.
8. Refer to C5 above. Then check air
gap.
9. Overloaded or locked compressor.
9. Repair or replace compressor.
10. Icing.
10. Check for suction line frosting.
Replace expansion valve if
necessary.
Replace receiver/drier if necessary.
D.
1. Motor and/or blades improperly
1. Check mountings, adjust as
CONDENSER
mounted.
necessary.
VIBRATION
2. Foreign matter build-up on
2. Clean blades with a suitable
blades.
non-inflammable cleaner.
3. Excessive wear of motor bearings.
3. Replace motor.
