What Are the Reasons for the Air Conditioning Not Cooling in the Car?
3 Answers
The reasons for the air conditioning not cooling in the car are: 1. Insufficient or too little refrigerant; 2. Excessive refrigerant; 3. Loose drive belt of the car air conditioning compressor; 4. Unqualified refrigerant and refrigeration oil; 5. Moisture infiltration into the refrigeration system. Solutions for the air conditioning not cooling in the car: 1. Add refrigerant; 2. If there is too much refrigerant, slowly release some from the low-pressure side maintenance port of the air conditioning system; 3. Replace the drive belt with a new one; 4. Re-inject an appropriate amount of refrigerant. The air conditioning in the car is used to adjust and control the temperature, humidity, air cleanliness, and air flow in the car compartment to an optimal state, providing passengers with a comfortable riding environment and reducing travel fatigue.
I've been repairing cars for many years and have seen many issues with air conditioning not cooling. The reasons can actually vary quite a bit. The most common is refrigerant leakage, meaning the AC fluid has all leaked out, which causes the air to blow warm. Compressor failure is also a frequent problem—it wears out or seizes up under high temperatures, resulting in a humming noise when the fan runs but no cold air. Blown fuses are also common; just open the fuse box and check if the fuse for the AC is intact. A clogged condenser affects heat dissipation—the fan may work normally, but cooling performance is poor. Aging wiring or loose connections can also cause system failure. If you notice the AC isn’t cooling, first check if the filter is clean—if it’s clogged, air can’t get through, and low airflow naturally means less cooling. It’s best not to delay—driving without AC in summer is dangerous and can easily lead to heatstroke. Head to the repair shop quickly—they have professional tools to detect leaks and check system pressure.
My car's AC wasn't cooling before, making it unbearably hot. A friend suggested it might be low on refrigerant and just needed a top-up. However, it could also be due to a faulty AC compressor making unusual noises when running, or a clogged expansion valve causing high-pressure overheating. A dirty filter blocking airflow can reduce cooling efficiency, so regular cleaning helps prevent this. A blown fuse is an easy fix—just try replacing it. Another possibility is poor condenser heat dissipation, where a non-functioning fan or damaged blades impair cooling. For a quick self-check: start the car and listen for compressor sounds, then set the fan to maximum to test if the hot/cold switching works smoothly. If not, visit a professional shop—don’t delay, as long drives without AC in hot weather are miserable. Remember to maintain it timely with seasonal checks to prevent issues.
