Why does the car air conditioner sometimes work and sometimes not?

[AryaAnn]

Reasons why the car air conditioner sometimes works and sometimes not are as follows: 1. Compressor: The compressor capacitor is damaged or faulty, causing the compressor not to work (the phenomenon is similar to the above, but the compressor does not rotate and overheats). 2. Temperature sensor resistance: The resistance value of the room temperature sensor changes, causing the external unit of the air conditioner not to work (the phenomenon is the same as when the air conditioner stops after reaching the set temperature). 3. Remote control: The remote control is faulty or the air conditioner receiver is not working (manifested as no response when turning on the air conditioner, or intermittent failure). 4. Four-way valve or compressor: The four-way valve (this fault does not occur in single-cooling machines) or the compressor has high and low pressure gas leakage, the air conditioner works but has no effect (the phenomenon is the same as the first one). 5. Live and neutral wires: The live and neutral wires of the air conditioner power supply are reversed (a few air conditioners may have this fault, usually during installation).

[Kathy]

My old car had this exact issue - the AC would work intermittently, leaving me sweating buckets. The most likely culprits are either a faulty compressor clutch causing intermittent engagement, or loose wiring connections that disconnect when hitting bumps. Don't overlook refrigerant leaks either - low pressure triggers system protection shutdown. Electrical components like blown fuses or aging relays can also cause this. I'd suggest first checking your fuse box yourself. If those are fine, take it to a repair shop for diagnosis - don't delay or you'll suffer through summer. Regular AC system maintenance helps too - clogged filters restrict airflow.

[MacAdaline]

The air conditioning blower sometimes works and sometimes doesn't. Common issues include the compressor clutch failing to engage consistently, intermittent short circuits in the wiring, or control panel malfunctions. I think sensor problems are also significant, such as a faulty temperature probe causing the system to misjudge the temperature and cycle on and off. Loose electrical connections are common in older cars, disconnecting and reconnecting when the car bumps around. It's best to check the fuses and refrigerant pressure; abnormal pressure might indicate a leak. Have a professional mechanic test the circuits with a multimeter and fix it early to avoid overheating and distractions on the road.

[DiRafael]

Intermittent air conditioning failures are often caused by electrical component issues, such as burnt relay contacts leading to poor connection, worn compressor clutch failing to engage, or insufficient refrigerant triggering automatic system shutdown. Check for loose wiring connections and intact fuses. Sensor malfunctions like unstable pressure switches may also cause intermittent operation. It's recommended to have a comprehensive inspection at a repair shop, and do not overlook the risk of refrigerant system leaks.