Why is the high pressure of car air conditioning so high?

[OXavier]

The reasons for the high pressure in car air conditioning are as follows: 1. Incomplete evacuation during maintenance, leading to air mixing into the system and increasing the condensation pressure; 2. Use of inferior refrigerant, the condenser electronic fan cannot open normally or the wind speed is insufficient; 3. The condenser is blocked by foreign objects and cannot dissipate heat normally, or the expansion valve is slightly blocked. If both high and low pressure values are measured to be too high, the reasons are as follows: 1. There is air in the system, and the system should be completely evacuated and refilled with refrigerant. 2. The system is blocked, mostly due to expansion valve blockage or failure, and the solution is to replace the expansion valve. 3. Excessive refrigerant, the system should be completely evacuated and refilled with a quantitative amount of refrigerant. 4. The condenser does not cool properly, and the solution is to clean the dirt from the condenser and radiator grille, and replace them if necessary.