1, refrigerant leakage. (The internal and external machines are both working, and the compressor is also working, but it is ineffective);

2. The compressor capacitor is damaged or defective, resulting in the compressor not working (the phenomenon is similar to the above, but the compressor does not turn and is overheated);

3. The resistance value of the temperature sensor changes at room temperature, resulting in the outdoor unit of the air conditioner not working (the phenomenon is the same as stopping the air conditioner after reaching the set temperature);

4. The remote control is not good or the air conditioner receiver is not good.

5. The four-way valve (the single cooler has no such fault) or the compressor leaks gas at high and low pressure, and the air conditioner works but has no effect (the phenomenon is the same as the first one);

6. The air conditioner does not cool due to the failure of the control panel of the internal unit or external unit of the air conditioner. (There is no response when the air conditioner is turned on or tampered with);

7. The zero line of air conditioning power supply is reversed. (A few air conditioners will have this kind of fault, usually during installation);

8. The fan of the internal machine or external machine is damaged (there are many bad capacitors). (The fault fan of the external machine is characterized by high exhaust temperature or high pressure protection. The bad fan of the internal machine is characterized by frosting of the internal machine, continuous operation of the external machine and dew condensation of the internal machine. ).

9. Other reasons

For example, the low power supply and voltage will reduce the suction of the compressor electromechanical clutch, or there is oil pollution between the pressure plate and pulley of the electric clutch, which will lead to the phenomenon of "slipping" similar to the loosening of the drive belt. If the surface of evaporator is frosted, the speed of blower motor will decrease, which will also cause insufficient cooling capacity. Of course, if the compressor is worn or the valve is improperly closed, it will also cause insufficient cooling capacity of the air conditioner.

The failure of air conditioning refrigeration system, such as insufficient refrigeration and poor refrigeration effect, is generally due to the problem of refrigeration seal. Because the refrigerant used in automobiles is very permeable now. Therefore, the sealing requirements of the system are also relatively high, and a slight leakage of the refrigeration working pipeline or valve will cause the failure phenomenon of insufficient refrigeration.