The biggest headache for many netizens in the summer is that the car’s cold and air conditioners are sometimes not. So what causes the cold and air conditioners to be hot and cold? Let's take a look now.
First, when the engine is working, the compressor is driven by the compressor belt, and then the AC switch is turned on and the compressor clutch sucker is sucked and then the refrigerant cycle in the air conditioning system is pushed to achieve the purpose of cooling. The reason why the cold air conditioner will appear hot and cold is because the compressor is constantly working and stopping repeatedly. Next, let's see what causes the compressor to trip frequently.
The first is the heat dissipation of the electronic fan. In fact, the air-conditioning electronic fan has two gears, one is a low-speed gear, and the other is a high-speed gear. When the cold air conditioner is turned on, the low-speed gear of the electronic fan will keep running, and then the heat sink reaches a certain level. The electronic fan will start the high-speed gear when the temperature is higher. If the temperature of the electronic fan is higher, the high-speed operation temperature of the electronic fan cannot be lowered, and the protection device needs to be activated to forcibly stop the compressor. Once the compressor stops working, the air conditioner will not be cooled , After the temperature drops, the compressor will restart to work, so the air conditioner will be hot and cold.
The second is that the air conditioning system is too dirty, such as clogged drying bottle, clogged expansion valve or evaporator, clogged radiator and so on. Because the air-conditioning system is too dirty to prevent the refrigerant from circulating better, the pressure of the air-conditioning system is too high, which affects its normal heat dissipation, and then the compressor will start the protection device to stop working, wait for the temperature and pressure The compressor will not start working again until it is slowly lowered, so the air conditioner will also be hot and cold.
The third possibility is the problem of the evaporator temperature sensor. Its function is to detect whether the evaporator is frozen. When it freezes, the compressor will stop working. If there is a problem with the sensor at this time, the signal will be misjudged and the evaporator cannot be accurately sensed. The specific temperature will also cause the compressor to start and stop frequently, and the air conditioner will also be hot and cold. Then we prepared a bottle of ice water and an alcohol lamp to watch the compressor start and stop when the sensor puts the ice water and the fire........You can see that the compressor stops working in the ice water. Set fire to work immediately.
Final summary: So all of the above will cause our car's cold and air-conditioning to be sometimes unavailable, but the most common is that the air-conditioning system is too dirty, causing excessive pressure and unable to better heat dissipation in time, so we can only clean or replace blocked accessories.