Why is the air conditioning not cooling even when the AC is turned on?

[StGriffin]

Here is an introduction to the car air conditioning AC button: 1. The AC button is the cooling switch for the car air conditioning. When pressed, the air conditioning compressor starts working, and the air blown out by the blower becomes cold. 2. For example, during hot summer days, to lower the temperature inside the car, press this button and turn the temperature selector switch to the blue part, and cold air will blow out. 3. If equipped with automatic air conditioning, simply press the AC button followed by the AUTO button. The automatic air conditioning will adjust the interior temperature based on the difference between the inside and outside temperatures.

[StEmilio]

As someone who works with cars year-round, I've seen way too many cases where the AC blows hot air despite being turned on – it's really common. The most frequent issue is insufficient refrigerant, which could be due to leaks in the piping or aging system seals failing. Another major culprit is compressor problems, like a burnt-out motor or a disengaged clutch preventing it from working entirely. A stuck fan can also hinder heat dissipation, and a condenser clogged with dirt and dust is another big reason. Electrical faults, such as blown fuses or faulty relays, also happen often. I recommend car owners pop the hood first and listen for the compressor's humming sound – if it's silent, check the fuse box or get the electrical system inspected immediately. Never attempt to top up refrigerant yourself; professional equipment is needed to measure pressure safely, or you risk damaging the car or even personal injury. Driving without AC in hot weather is especially dangerous, increasing fatigue and accident risks, so getting an early diagnosis at a repair shop is best. For routine maintenance, I suggest cleaning condenser fins annually and checking hoses for cracks to avoid future headaches.

[McAbel]

I once experienced my car's AC not cooling. That summer day was unbearably hot, and when I turned on the AC, it blew out hot air. After checking, I found out it was due to a refrigerant leak—there was hardly any left in the system, likely caused by aging hoses. It could also have been a faulty compressor that wouldn’t engage, a blocked fan that wouldn’t spin, or poor heat dissipation. Some suggested issues like a clogged expansion valve, but personally, I think checking a blown circuit fuse is the easiest—just look for the corresponding mark in the fuse box. Back then, I quickly took it to a repair shop where they used instruments to measure the pressure and fixed it, saving me from the risk of DIY mishaps. My experience tells me that driving without AC in extreme heat can easily lead to heatstroke or fainting, especially on highways, so it’s best to pull over, open the windows for ventilation, and seek professional help immediately. Regular AC maintenance, like cleaning dust from the evaporator, can really prevent such issues in advance.

[MarianaRose]

Buddy, when the AC is on but no cold air comes out, I know this issue well. Common problems include insufficient refrigerant, not knowing where the leak is; the compressor might be completely out of order; the fan could be stuck, slowing down heat dissipation; or a blown fuse cutting off power. I suggest you do a simple self-check first: start the car and turn on the AC, listen for the compressor sound in the engine bay—if it's quiet, check the fuse box. Don't mess with the refrigerant yourself; that stuff needs professional handling to avoid explosion hazards. If there's really a problem, get it fixed ASAP—safety first.