The working environment of automobile air conditioners is extremely harsh. Long-term vibration and corrosion will cause system leakage and reduced reliability. The compressor is a high-speed running equipment in the air-conditioning system. The wear and tear of high-speed running parts will cause the performance of the compressor to decrease. At the same time, the micro-dust formed by the wear will contaminate the refrigeration oil, block the system, and cause compressor and system failure. Therefore, the system must be maintained on schedule.
1. Inspection of refrigerant
Turn on the air conditioner and set the temperature to the lowest setting. After running for 10 minutes, open the return air grille and observe the liquid sight glass from the return air outlet. If the liquid surface is clear and has no bubbles or bubbles are occasionally seen within 45 seconds, it means that the refrigerant is sufficient; if there are a lot of bubbles, it means that there is a lack of refrigerant and needs to be replenished refrigerant.
Note: If the R407C refrigerant used in all-electric air conditioners leaks and the leakage exceeds 5%, it cannot be recharged directly. It needs to be completely drained and then refilled in liquid form.
2. Cleaning of filter
Open the return air grille at the roof of the car, remove the return air grille dust screen, check the cleanliness of the dust screen, and use compressed air to clean the dust screen if necessary. If the dust filter is dirty or clogged, wash it in warm water mixed with neutral detergent, rinse it with clean water and dry it completely.
3. Condenser cleaning
(1) Remove the condensing fan or protect it with plastic cloth.
(2) Rinse the heat sink with high-pressure water. Pay attention to control the pressure and do not damage the radiator by being too high. If the blockage is serious, you need to scrape off the oil stain first, and then clean it with neutral detergent.
(3) Clean the dirt inside the condenser.
4. Cleaning of evaporator
(1) Remove the evaporator fan or protect the fan with plastic cloth
(2) Protect the electric control box and return air outlet with plastic sheeting to prevent water from entering the car.
(3) Other steps are the same as cleaning the condenser.
5. Cleaning of return air grille
Open the return air grille at the top of the car, remove the return air grille dust screen, check the cleanliness of the dust screen, and use compressed air to clean the dust screen if necessary. If the dust screen is dirty or clogged, please wash it in warm water mixed with neutral detergent. If it is clogged, wash it in warm water mixed with neutral detergent. Rinse it with clean water and completely dry
6. Inspection of electronic control system
(1) Every interface of the air conditioner electronic control system must be in good contact, otherwise the air conditioner will not work properly.
(2) Check whether the connectors between the air conditioner controller and the wiring harness on the instrument panel, the wiring harness in the air duct and the evaporator electrical control box, and the compressor and wiring harness are in good contact, and whether the connections are in place.
(3) Check whether the relay and fuse in the air conditioner electrical control box are intact and whether the connections are in place.
(4) Check whether the power cord of the air conditioning system is in good contact with the generator, fuse box, and evaporator wiring bolts.
(5) Check whether the grounding of the return air conditioning electronic control system is good.
(6) Check whether high-voltage electrical components such as compressors, DC modules, electrical control boxes, and high-voltage wire harnesses are damaged or burned. If the above conditions occur, replace the relevant electrical components.
(7) Detect the insulation resistance of the positive electrode of the air-conditioning high-voltage electrical device to the casing and the high-voltage negative electrode of the high-voltage electrical device to the casing respectively.
If the insulation resistance is lower than the vehicle alarm value, replace the relevant electrical components.
