What Causes the Car Air Conditioner to Alternate Between Hot and Cold?
2 Answers
Introduction to the reasons why a car air conditioner alternates between hot and cold: 1. Damaged compressor capacitor: For the air conditioner to function properly, both the internal and external units need to work together. If the car air conditioner exhibits alternating hot and cold air, 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 hasn't been cleaned for a long time, it can also cause the air conditioner to alternate between hot and cold. A dirty filter or evaporator can easily 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 temperature inside the car alternates between hot and cold, check if the refrigerant in the air conditioning system is insufficient. If so, use other methods to address the issue. 4. Moisture in the air conditioning system: When high-temperature, high-pressure liquid passes through the expansion valve, all the liquid undergoes a rapid change, turning into low-temperature, low-pressure liquid. This low-temperature, low-pressure liquid causes the temperature of the evaporator to drop rapidly, so the air blown by the air conditioner motor becomes cold after passing through the evaporator.
Last month, my car's air conditioning was acting up—sometimes freezing cold like a fridge, other times unbearably hot, which was really annoying. I took it to the repair shop that day, and the mechanic checked the refrigerant, finding a leak that caused unstable pressure in the system, making the AC work intermittently. He also mentioned the compressor might have some issues, and if the pressure was insufficient, the fan speed would fluctuate. I usually make sure to replace the air filter regularly, and it wasn’t dirty, but this inspection revealed a small crack in the piping, possibly due to rough road conditions and bumps. I’d advise everyone not to delay—get it checked by a professional ASAP to avoid distractions and accidents on the road. Driving in summer without AC is unbearable, and spending a little to fix it saves a lot of hassle.