What is the reason why the car air conditioner stops cooling after running for a while?
4 Answers
Car air conditioner stops cooling after running for a while because the condenser is covered by pollutants, so it needs to be cleaned regularly. Cleaning can be done with an air gun or a water gun. Here are some methods to solve the problem of car air conditioner not cooling: 1. Clean the condenser and filter screen. If the condenser inside the air conditioner is too dirty, it needs to be cleaned in time. Dust will accumulate on the condenser, causing poor heat dissipation and seriously affecting the cooling effect. First, prepare a bucket of water and carefully wipe the condenser with a cloth to remove dust and stains. 2. The air conditioner filter screen is blocked, causing the car air conditioner not to cool. At this time, the air conditioner filter screen needs to be cleaned. If the filter screen is severely damaged or has reached the end of its service life, it can be replaced directly. 3. Add refrigerant and test the cooling effect of the air conditioner. If it cannot cool normally, it may be due to insufficient refrigerant in the air conditioning system. Since the amount of refrigerant sprayed into the evaporator from the expansion valve is reduced, the heat absorbed by the refrigerant is too little, resulting in poor cooling effect. At this time, refrigerant should be added.
Last time I was driving, the air conditioning was cool at first, but after a while it stopped cooling. I looked it up and found there are quite a few possible reasons. The most common one is refrigerant leakage—that stuff can slowly leak out over time, and if the compressor doesn't have enough pressure, the cold air won't come out. Also, if the fan is broken or the condenser is clogged, it can cause poor heat dissipation, leading the AC system to overheat and shut down as a self-protection measure. I once experienced the fan getting stuck while the AC was running, and the whole car heated up. Compressor wear is another issue—like internal parts aging, where it works at first but then stops after a while. There's also the expansion valve getting stuck, restricting refrigerant flow and only allowing short bursts of cooling. When repairing, it's important to check the sealing of the pipes, otherwise frequent fixes can get expensive. A buzzing noise when the AC is on could also be a warning sign—it's safer to get it checked at a professional shop early, so you don't end up sweating on a long summer drive.
I often help friends with car issues. If the AC doesn't cool after prolonged use, it's usually due to system dust buildup or condenser blockage. Excessive dust reduces heat dissipation, causing the AC to overheat and shut down. Insufficient refrigerant is another major cause - low compressor pressure prevents sustained cooling, especially in older cars prone to refrigerant leaks. Faulty fan motors can also cause this; if they don't spin, heat dissipation fails. Pressure switch malfunctions may disrupt operation if current isn't properly controlled. Start with simple checks like replacing cabin filters or testing refrigerant levels before moving to compressor inspection. My last repair cost several hundred dollars - regular maintenance saves trouble. While driving, prevent leaves/debris from entering air intakes to avoid overloading and damaging the AC system.
I've experienced the car's AC turning warm after just ten minutes of operation in summer, most likely due to a faulty compressor. Worn internal seals cause insufficient pressure, interrupting cooling. Alternatively, refrigerant might be leaking faster than it's being replenished, preventing the system from maintaining pressure. Another common issue is a dirty or clogged condenser impairing heat dissipation—cleaning it often solves the problem. Electrical problems like poor relay contact can also cause intermittent power loss. For frequently used AC systems, check refrigerant levels and wiring in advance to prevent minor issues from escalating. If cooling is insufficient, it's best to stop immediately and inspect the fan and belts. Regularly rinsing the AC system during car washes helps prevent clogs.
