What Causes Ice Formation in the Car's Evaporator Box?

[DiHayden]

There are several reasons for ice formation in the car's air conditioning evaporator box: 1. The expansion valve's adjustment is too small, resulting in excessively low low-pressure. 2. Insufficient refrigerant in the system leads to excessively low evaporation pressure. 3. The internal circulation filter is clogged. 4. The temperature control (or temperature sensor) malfunctions, causing the compressor to run continuously. 5. The variable displacement compressor's energy control valve (pressure regulating valve) fails, keeping the compressor operating at full capacity, which results in excessively low low-pressure and causes the evaporator to freeze. Below are solutions for ice formation in the car's air conditioning evaporator box: 1. Check if the temperature control sensor is in the correct position. 2. Adjust the temperature control to a lower setting; if it cannot be adjusted, replace the temperature control. 3. Inspect the air conditioning computer control for any faults. 4. Apart from the compressor running continuously, check if the evaporator box fan's inlet and outlet dampers are blocked.