What are the reasons for a diesel car's air conditioning not cooling?

[BriellaDella]

Here are the reasons why a diesel car's air conditioning may not be cooling: 1. Refrigerant: Refrigerant leakage (manifested as both the indoor and outdoor units working, the compressor also working, but with no effect). 2. 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). 3. Room temperature sensor: The resistance value of the room temperature sensor changes, causing the outdoor unit of the air conditioner not to work (the phenomenon is the same as when the air conditioner stops after reaching the set temperature). 4. Remote control: The remote control is faulty or the air conditioner receiver is faulty (manifested as the air conditioner not responding when turned on, or working intermittently). 5. Four-way valve: The four-way valve (single-cooling units do not have this fault) or the compressor's high and low pressure air is mixed, the air conditioner works but has no effect (the phenomenon is the same as the first one). 6. Air conditioner: The control board of the indoor or outdoor unit of the air conditioner is faulty, causing the air conditioner not to cool (manifested as no response when turned on or erratic operation). 7. 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).

[DeMiles]

Oh, I've encountered the issue of diesel car air conditioning not cooling several times, and I think there are quite a few reasons. The most basic one is insufficient refrigerant—it's like a water tank running dry, the system pressure gets too low, and once the refrigerant is gone, the AC is done for. If the compressor is broken, it's even more serious; it's responsible for compressing the refrigerant into a liquid, and if it's not running properly, the fan won't spin fast either. A clogged condenser or a faulty fan can lead to poor heat dissipation, causing the whole system to overheat. Don’t underestimate electrical issues either—blown fuses and burnt relay contacts are quite common, and a short circuit can bring everything to a halt. A dirty air filter blocking airflow is also a culprit. I recommend regular maintenance to check refrigerant levels and ensure there are no leaks in the piping system. If a problem arises, don’t force it—head to a professional repair shop immediately to avoid accidents. Addressing these small issues promptly ensures a worry-free drive and keeps summer travel stress-free.