What could be the reason when a car's air conditioning suddenly stops responding?

[McMia]

The reasons why a car's air conditioning suddenly stops responding: 1. Possible pipe blockage, excessively high pressure or low pressure; 2. Poor heat dissipation; 3. Expansion valve blockage; 4. Too little or too much refrigerant; 5. Compressor not operating. Below are related solutions: 1. Check the pressure of the refrigerant. If the pressure is too low, the refrigerant is insufficient and needs to be replenished. Insufficient refrigerant will affect the air conditioning's cooling. 2. Check whether the blower of the air conditioning system is operating normally and the amount of air flow. If there is a problem with the blower, the cold air from the air conditioning system cannot be delivered to the car interior in time, resulting in no cold air from the air conditioning vents. 3. Check whether the surface of the air conditioning system's evaporator is too dirty. If the surface of the evaporator is too dirty, the cold air from the air conditioning vents will decrease because the cold air is mainly produced by the evaporator. 4. The working cycle of the refrigerant in the pipes must rely on the compressor for transportation. If the compressor cannot operate due to abnormal refrigerant pressure, circuit failure, temperature sensor damage, or burned compressor electromagnetic clutch, the cooling will be insufficient. It is recommended to replace the temperature sensor or electromagnetic clutch.

[DeOscar]

That day, my car's air conditioning suddenly stopped working, so I quickly pulled over to check. First, I popped the hood to see if the AC fuse had blown—common locations are under the steering wheel or in the engine bay fuse box. If it's blown, just replace it with a new one; a quick fix for a minor issue. It could also be the compressor not engaging or an electrical short. Check if the fan is running—if not, it might be poor electrical contact. I've encountered this before, and it's especially troublesome in hot weather. That's why during routine maintenance, I always remind the mechanic to inspect the AC system to avoid summer driving misery, saving repair time and giving peace of mind. Additionally, a faulty temperature sensor can trigger a protective shutdown, requiring professional tools to diagnose. But in most cases, don’t rush to spend big—start troubleshooting from the simpler possibilities.

[ValerieLee]

As a frequent road-tripper, I get nervous whenever the AC stops working. First, I check if a fuse has blown—usually found in the car's fuse box—and replace it with a cheap one if needed, which takes just minutes. If that doesn’t fix it, the issue might be a faulty compressor clutch or refrigerant leak, where the system shuts down automatically due to low pressure. In that case, head to a professional shop for a refrigerant recharge to avoid damaging other parts. A non-spinning fan could also indicate a motor issue; check if the blades are stuck. I recommend keeping an emergency toolkit handy. Stay calm, ensure proper ventilation, and troubleshoot step by step—handle minor fixes yourself and leave major issues to mechanics to save money and hassle.

[Wayne]

Last time during a long-distance drive, my air conditioning suddenly stopped without warning, so I immediately pulled over and turned off the engine to inspect it. The key was to check if the fuses were intact—replace them if blown. It could also be a compressor failure or a short circuit in the wiring. If the temperature gets too high, first open the windows to cool down and avoid heatstroke risks, then gradually check the air conditioning control module for abnormalities, such as malfunctioning buttons or sensors falsely reporting pressure changes. During regular maintenance, I always ask the technician to inspect the AC pipes and refrigerant levels—top it up if there’s a minor leak, as preventive maintenance is the most cost-effective. Remember, safety comes first—never force yourself to drive a hot car on the highway.