When the surface temperature of the

When the surface temperature of the evaporator is too low, the water droplets on the evaporator surface and the surrounding water vapor condense ice and adhere to the evaporator surface. After the surface of the evaporator is frosted, the resistance of air entering the cab through the evaporator will increase, resulting in a decrease in the air outlet and a rise in the temperature of the cab.Fault phenomenon: during the normal road test of the car, the air volume at the outlet of the instrument panel attenuates until the fault occurs when there is no wind. Road test personnel feedback, get off to check the front of the vehicle, air conditioning high pressure pipe frost, according to previous experience, preliminary judgment air conditioning evaporator frost.Troubleshooting: check the insertion position of evaporator temperature sensor. Check whether the insertion position of the evaporator core temperature sensor meets the design requirements. After sampling inspection, the insertion positions of all product temperature sensors are in accordance with the requirements of the diagram.Check whether the insertion point of evaporator temperature sensor is reasonable. The temperature sensor can choose neither the highest temperature nor the lowest temperature. Select the highest temperature, when it reaches 3℃, the temperature at other points is already below 0℃, and the evaporator will have a large area of frost. Select the lowest temperature, when reaching 3℃, the temperature at other points is too high, resulting in insufficient refrigeration. The location of the temperature sensor should be selected when the location here reaches 3℃, the highest temperature is above 0℃, the lowest temperature is below 0℃, and the evaporator surface starts to frosted at 20%~25% of the area, the location is the best, meeting the requirements.Foreign matter can affect evaporator place only temperature sensor plug, plug view so the enclosure, found the temperature sensor is fixed in the evaporator pipe connector position holder directly, if long time to open air conditioning, linking piece can form condensate, if has condensed water drip into the sensor in the plug-in, may cause the temperature sensor error.