HVAC
28
TROUBLE SHOOTING
Sr.NO.COMPLAINT
POSSIBLE CAUSE
REMEDY
1
Insufficient flow of cold air
1. Evaporator clogged or frosted.
2. Air leaking from cooling unit or
air duct.
3. Air inlet blocked.
4. Blower motor faulty.
1. Check evaporator.
2. Repair as necessary.
3. Repair as necessary.
4. Replace blower motor.
2
Blower won't work even
when its switch is ON
1. Blower fuse blown.
2. Blower motor faulty.
3. Wiring or grounding faulty.
1. Replace fuse.
2. Replace motor.
3. Repair as necessary.
3
Incorrect
temperature
output
1. Control cables broken or bind-
ing.
2. Control cables not connected
properly.
3. Air ducts clogged.
4. Heater matrix leaking or choked.
5. Heater hoses leaking or choked.
6. Kinematics jammed.
1. Check cables.
2. Connect cables properly.
3. Repair air ducts.
4. Replace heater matrix.
5. Replace hoses.
6. Repair/Replace kinematics.
4
Cold air comes out only
intermittently
1. Magnetic clutch slipping.
2. AC relay faulty.
3. Expansion valve faulty.
4. Wiring connection faulty.
5. Excessive moisture in the sys-
tem.
6. Faulty thermistor cut-in and/or
cut-off setting.
1. Check magnetic clutch.
2. Replace faulty relay.
3. Check expansion valve.
4. Repair as necessary.
5. Evacuate and charge AC
system.
6. Replace thermistor.