The car air conditioner is very loud, but why the sound becomes normal when the inner loop is turned on?
Check:
1. Whether the exhaust window blades are loose;
2. Whether the driving belt of the air conditioner compressor is loose or worn;
3. Whether the air-conditioning compressor installation bolts are loose;
4. Listen carefully for noise from the air-conditioning compressor;
5. Air conditioner compressor wiring and solenoid valve.
Judgment:
1. The compressor coil and solenoid valve are faulty;
2. The compressor liquid level is too low;
3. Fan fan failure;
4. If there is too much moisture in the system, the expansion valve will be noisy;
5. If the high-pressure side servo valve is closed, the compressor will produce knocking noise.