Why Won't the Car Air Conditioning Compressor Start?
3 Answers
Detailed reasons and solutions for car air conditioning compressor failure to start are as follows: 1. Severe internal wear of the compressor, leading to malfunction: Check the throttle valve position for iron filings. Excessive filings indicate compressor wear, necessitating replacement of a new air conditioning compressor. Solution: Replace with a new air conditioning compressor. 2. Insufficient refrigerant (Freon) in the car air conditioning system. Solution: Replenish refrigerant. 3. Fault in the car's electrical system: Requires circuit inspection. Solution: Inspect and repair the circuit. 4. Abnormal pressure in the car air conditioning system: Blockage or leakage in the air conditioning pipes can cause abnormal system pressure. Solution: Inspect and repair the air conditioning pipes. 5. Insufficient refrigerant in the car air conditioning compressor: Depletion of Freon in the refrigerant affects insufficient return of refrigeration oil, reducing compressor lubrication and causing jamming or damage. Solution: Replenish refrigerant.
I just encountered an issue with the air conditioning compressor not starting last month, and it took me a lot of effort to figure it out. The most common cause is insufficient refrigerant, where a system leak leads to too low pressure, and the compressor's protection mechanism won't engage. Another possibility is electrical issues, such as a short circuit in the air conditioning control panel wiring or oxidized relay contacts, preventing the signal from getting through. The compressor itself could also be faulty, like a burned-out electromagnetic clutch coil or seized bearings. If the belt is broken or too loose, it won’t be able to drive the compressor either. I remember that day, after refilling the refrigerant, it still didn’t work—later, I found out the pressure sensor was faulty. In short, the air conditioning system is complex, so it’s best to take it to a professional shop for diagnosis rather than trying to fix it yourself and risking making it worse.
During my car repairs, I often encounter cases where the compressor fails to start. To summarize, the issues mainly fall into three categories. First, the power supply: the battery has insufficient charge to power the compressor, a blown fuse interrupts the current, or the relay coil is aged and fails to engage. Second, control system failures: the air conditioning control module is burnt out or has program errors, the temperature sensor fails and misjudges the cabin temperature, or the pressure switch malfunctions and cuts off the circuit. Third, mechanical problems: the compressor is internally jammed and cannot rotate, the clutch gap is too large to engage, or the belt slips and fails to transmit power. Just yesterday, a car owner had a module burn out due to unstable voltage, and replacing the module solved the issue. Such problems require systematic troubleshooting, and it is recommended to allocate at least half an hour for inspection.
