What Causes Car Air Conditioning Not to Cool and How to Repair It?
2 Answers
Car air conditioning not cooling properly can be caused by the following reasons and repaired accordingly: 1. Excessive refrigerant leading to insufficient cooling. This can be observed through the sight glass on the dryer tank. If no bubbles are visible in the sight glass while the car air conditioning is running, and no bubbles appear after the compressor stops, it definitely indicates excessive refrigerant. If the pressurized cooling oil is too much, slightly turbid bubbles can be seen in the sight glass during normal operation. If the refrigerant is indeed excessive, some can be slowly released from the low-pressure side service port of the air conditioning system. 2. Insufficient refrigerant due to low levels. This can also be observed through the sight glass on the dryer tank. During normal operation, if continuous slow bubbles appear in the sight glass, it indicates insufficient refrigerant. If obvious bubble flipping occurs, it signifies a severe shortage of refrigerant. If the refrigerant is insufficient, it should be added. However, note that when adding from the low-pressure side, the refrigerant bottle must not be inverted, and when adding from the high-pressure side, the engine must not be started. 3. Excessive impurities in the refrigerant and lubricating oil causing micro-clogs and reduced cooling capacity. 4. Moisture infiltration into the air conditioning system leading to insufficient cooling. Repair method: Stop the system for a while until the ice melts, and the system will return to normal. This is an important method to confirm the presence of moisture in the system. To better detect the amount of moisture in the system, some cars use desiccants that are blue when dry but turn red when moisture is excessive, which can be seen through the side sight glass on the dryer tank.
Last time my car's AC suddenly stopped cooling, I wondered if it was low on refrigerant—the most common issue. Sometimes it's due to aging pipes leaking Freon, or a faulty compressor making buzzing noises. If the fan stops working or the condenser gets clogged with dust, the cold air can vanish too. When troubleshooting, start simple: check refrigerant pressure—top it up and inspect for leaks if low; test if fuses are blown and replace them; clean the condenser and fan blades. But don’t DIY—high-pressure systems are risky, and damaging pipes could worsen things. I took it to the shop, where the mechanic used professional tools to diagnose a faulty compressor. After spending a bit to replace it, everything works fine now. I regularly maintain my car, cleaning the AC filter to prevent such issues on the road. Before summer drives, I test the AC to ensure safe travels.
