VENTILATION, HEATER & AIR CONDITIONER › HEATER & AIR CONDITIONING CONTROL SYSTEM › SYMPTOM DIAGNOSIS

NOISE

AUTOMATIC AIR CONDITIONER

Description
Diagnosis Procedure

Description

Symptom

Noise
Noise is heard when the A/C system operates.

Diagnosis Procedure

1.CHECK OPERATION

Operate the A/C system and check the operation. Refer to Description & Inspection.
Check the parts where noise is occurring.

Can the parts where noise is occurring be checked?

YES‐1>>Noise from blower motor: GO TO 2.

YES‐2>>Noise from compressor: GO TO 3.

YES‐3>>Noise from expansion valve: GO TO 4.

YES‐4>>Noise from cooler piping (pipe, flexible hose): GO TO 6.

YES‐5>>Noise from drive belt: GO TO 7.

NO>>INSPECTION END

2.CHECK BLOWER MOTOR

Remove blower motor.
Remove foreign materials that are in the blower unit.
Check the noise from blower motor again.

Is the inspection result normal?

YES>>INSPECTION END

NO>>Replace blower motor.

3.CHECK COMPRESSOR

Perform trouble diagnosis for the compressor and check the compressor. Refer to Symptom Table.

Is the inspection result normal?

YES>>INSPECTION END

NO>>Refill the refrigerant or replace the compressor according to the inspection results.

4.CHECK WITH GAUGE PRESSURE

Perform the diagnosis with the gauge pressure. Refer to Trouble Diagnosis For Unusual Pressure.

Is the inspection result normal?

YES>>GO TO 5.

NO>>Repair or replace parts according to the inspection results.

5.CHECK EXPANSION VALVE

Correct the refrigerant with recovery/recycling recharging equipment.
Recharge with the proper amount of the collected refrigerant after recycling or new refrigerant.
Check for the noise from expansion valve again.

Are the malfunction solved?

YES>>INSPECTION END

NO>>Replace expansion valve.

6.CHECK COOLER PIPING (PIPE, FLEXIBLE HOSE)

Check the cooler piping (pipes, flexible hoses) (for deformation and damage, etc.).
Check the installation condition of clips and brackets, etc. of the cooler piping (pipes, flexible hoses).

Is the inspection result normal?

YES>>Fix the line with rubber or come vibration absorbing material.

NO>>Repair or replace parts according to the inspection results.

7.CHECK DRIVE BELT

Check tension of the drive belt. Refer to Checking.

Is the inspection result normal?

YES>>Check the noise from compressor: GO TO 3.

NO>>Adjust or replace drive belt according to the inspection results.