1. Failure report for repairA mark

1. Failure report for repairA mark 307, the owner in the use of air conditioning, air conditioning refrigeration system is normal, but the air outlet of the dashboard is not cool, especially when the outdoor temperature is above 30 ℃, feel the air outlet blowing out is natural wind.(1) fault checkThe first step is to comprehensively analyze and test the specific situation of refrigerant and strictly test the dynamic and static pressure of the system. The engine cover reasonable set up and fixed in the corresponding position, will start the protection equipment of high pressure pipe, suitable for high pressure of the exhaust ejector press operation will find refrigerant overflow condition at this time, need to take the high/low pressure of the air pressure gauge tube connected to the interface to system's internal corresponding reasonable, at the same time, the high and low pressure table values for 600 kpa, the static pressure in the system operation is normal.The second step is to make the engine of the vehicle enter the working state. While starting the A/C switch of the air conditioner, the internal and external circulation REC switch is also turned on, and the blower switch is adjusted to the third gear. At this point, the readings of the low and high pressure gauges were 180kpa and 1510kpa, respectively, also in the permissible range. It can be observed that the cooling electronic fan keeps rotating at a low speed and can feel a large temperature difference when touching the high and low pressure tubes. Based on the comprehensive analysis of the previous detection operation, the main body of the target vehicle air conditioning system is normal in the overall operation process. According to the accumulated maintenance experience for a long time to carry out a comprehensive judgment, the main reason for the refrigeration anomaly is not able to scientifically cut off the external heat source in the operation.The waterproof plastic plate under the windshield is still effective. At this time, the REC switch is set at the inner circulation position, while the movable damper cannot be closed effectively in the evaporation box on the right side. The installation position of the movable damper is shown in figure 4.3. Check the control of its opening and closing of the vacuum suction in practical operations of the specific circumstances, set off in the end of a vacuum bag vacuum tube will exist certain suction effect, on the basis of reasonable dismantled vacuum bag (specific diagram as shown in figure 4.4), check the gas leakage problems, and in addition to parts are no exception.