The electromagnetic clutch coil of the air conditioning is burned out. In addition to quality issues, the main reason is that the pressure of the air conditioning system is too high, causing excessive resistance to drive the compressor to operate. This exceeds the electromagnetic suction force of the electromagnetic coil, causing relative sliding friction between the main and passive discs of the clutch, leading to overheating and burning.

There are three reasons for high pressure in the air conditioning system:

① When parking, the engine runs at idle speed and the air conditioner is used in direct sunlight for a long time;

② When the radiator fan of the water tank malfunctions, the air conditioner is used for a long time and with high intensity (the radiator fan of the water tank is shared with the air conditioner condenser fan);

③ Excessive addition of Freon in the refrigeration system.

When the compressor starts working, pay attention to the observation window of the liquid storage tank and find that there are no bubbles inside the observation window. Connect the high and low pressure gauges to the refrigeration system again and check their pressure. It was found that the pressure on both the high and low sides deviated. Obviously, the refrigerant is overfilled. After removing the refrigerant from the low-pressure side in an appropriate amount (with a high-pressure side pressure of 1.2-1.8MPa and a low-pressure side pressure of 0.15-0.30MPa as appropriate), the fault is resolved.

To avoid such malfunctions, air conditioning should not be used in the following three situations.

① When the amount of refrigerant added exceeds the specified amount, it should be discharged in a timely manner, otherwise the air conditioner is not allowed to be used. The method to check the amount of refrigerant is to check whether there are any bubbles in the observation window of the storage tank when the compressor starts working. If there are no bubbles, it indicates that there is too much refrigerant and should be released in moderation. If there are too many bubbles, it indicates that there is too little refrigerant and should be added in moderation.

② When the cooling fan of the water tank malfunctions and stops operating, the air conditioner should be immediately stopped, otherwise the refrigeration system will generate ultra-high pressure, causing the electromagnetic clutch to slip and burn out.

③ When parking, it is best not to turn on the air conditioning when the engine is idling.