Why Does the Car Air Conditioner Blow Hot and Cold Intermittently?
3 Answers
Reasons for intermittent hot and cold air from the car air conditioner: 1. Damaged compressor capacitor: The air conditioner requires both the internal and external units to function properly. If the car air conditioner blows hot and cold intermittently, check if the external unit's compressor start capacitor is damaged. If so, it needs to be replaced. 2. Dirty filter: If the air conditioner has not been cleaned for a long time, it can also cause intermittent hot and cold air. A dirty filter or evaporator can lead to poor ventilation and heat dissipation, causing the compressor to overheat and shut down. Therefore, regular cleaning is necessary to maintain cleanliness. 3. Insufficient refrigerant: The air conditioner requires an adequate amount of refrigerant, commonly known as Freon, to cool. If the car's temperature fluctuates between hot and cold, check if the refrigerant in the air conditioning system is insufficient. If it is, it needs to be replenished promptly.
Having driven for decades, I've seen plenty of cases where the AC fluctuates between hot and cold. The most common cause is insufficient refrigerant or leaks, leading to unstable cooling—especially noticeable in summer. A stuck expansion valve can also cause erratic temperature shifts, and frequent compressor cycling makes issues worse. If the blend door is misaligned, hot and cold air won't mix properly; a faulty temperature sensor misreading data adds to the chaos. I've even encountered clogged cabin air filters disrupting airflow. For maintenance, biannual checks—replacing filters and topping up refrigerant—can prevent these nuisances. When unstable AC distracts you while driving, pull over safely, open windows, and ventilate. Never push through on long trips. Safety first: don’t risk skipping repairs to save money.
My new car has been running for over a year, but the AC keeps acting up with inconsistent cooling, which is really frustrating. I looked it up online and found it might be due to loose wiring connections causing intermittent signals, or a faulty switch button that doesn't function properly. I tried pulling out and reinserting the fuse myself, which sometimes provides a temporary fix, but if that doesn't work, I'll have to visit the repair shop. A friend's car had the same issue last time, and adding refrigerant solved it. If the temperature fluctuates while driving in summer, passengers will complain, affecting the travel experience. I regularly clean the filter to prevent clogging, and when the system works properly, it feels much better. Don't delay fixing such issues—address them quickly to avoid worsening. Being more maintenance-conscious makes driving more comfortable, saving both hassle and fuel.
