What are the methods for diagnosing car air conditioning faults?
1 Answers
When analyzing faults in the air conditioning system, they can be divided into two major parts for inspection: the circulation system components and the electrical control system. 1. Fault inspection and troubleshooting of the electrical control system. When the car's air conditioning is not cooling, the control system should be checked. If the control system is intact, then inspect the air conditioning circuit. 2. Diagnosis of the cooling system faults is generally conducted through a combination of sensory inspection and instrument diagnosis. (1) Sensory diagnosis. ① Use your eyes to observe the entire air conditioning system. First, check the flow status of the refrigerant in the sight glass of the dryer filter. Next, inspect whether the connections between all components and pipelines in the system are reliably sealed and whether there are minor leaks. Finally, check if the condenser is blocked by debris and whether the cooling fins are tilted or deformed. ② Use your ears to listen for any abnormal sounds from the operating air conditioning system. First, listen for any sharp noises from the compressor clutch. Then, listen for any liquid hammering sounds during the compressor's operation. ③ In the absence of a thermometer, you can touch the surfaces of various components and connecting pipelines of the air conditioning system with your hands. The high-pressure circuit should feel quite hot, while the low-pressure circuit should feel warm. (2) Instrument diagnosis. ① Leak detection with a leak detector. Use the leak detector to check for leaks at all connection points in the system. ② Pressure gauge inspection. Connect the high and low-pressure gauges of the manifold pressure gauge to the system's charging valves, and perform the inspection when the air temperature is between 30°C to 35°C and the engine speed is at 2000r/min.
