What Causes a Car Air Conditioner to Heat but Not Cool?

[Harvey]

There are several reasons why a car air conditioner may heat but not cool: 1. Damaged expansion valve: There's a saying in the air conditioning compressor world, "Low pressure high, high pressure low, replace the compressor." The probability of air conditioning compressor damage is not high, but faults in the expansion valve and throttle valve directly lead to poor air conditioning cooling. 2. Lack of refrigerant: Because the sealing device of the air conditioner is not absolutely airtight, the refrigerant in general air conditioners tends to dissipate. Therefore, ordinary vehicles need to add refrigerant every 2-3 years. Some cars may even require it once a year. If the car air conditioner performs poorly in cooling and starts to malfunction shortly after adding refrigerant, this usually indicates a condenser leak. The method to check for leaks is quite laborious. Generally, fluorescent dye is added to the refrigerant oil, and a special glass is used to inspect the system, allowing the leak point to be identified.