Why is the car air conditioner blowing air but not cold?
3 Answers
Car air conditioner blowing air but not cold is due to lack of refrigerant. The following is a relevant introduction about vehicle air conditioning: Concept: Vehicle air conditioning consists of a compressor, condenser, throttle element, evaporator, fan and necessary control components, which is an air conditioning system used to regulate the temperature and humidity inside the vehicle and provide a comfortable environment for passengers. The refrigerant continuously circulates in the system, with each cycle including four processes: compression process, condensation process, throttling process, and evaporation process. Working principle: When the compressor is working, it inhales low-temperature and low-pressure gaseous refrigerant from the evaporator. After compression, the temperature and pressure of the refrigerant increase, and it is sent to the condenser.
I've also encountered the issue of the AC blowing hot air before, and it usually boils down to these three common problem areas. First, check if there's enough refrigerant – if there's a Freon leak, cooling will definitely fail. Next, listen for any activity from the compressor; if you don't hear the 'click' of engagement when starting the car and turning on the AC, chances are the electromagnetic clutch is gone. Also, inspect the condenser – if the fins are clogged with willow catkins or insect debris, the compressor can work overtime to no avail. Last time, my cooling fan was stuck, causing the engine temperature to skyrocket and the AC to stop working. The most troublesome issue is blocked AC lines; if the expansion valve fails, the refrigerant won't circulate at all. Oh, and newer cars often have evaporator leaks, which require dashboard removal to fix – a time-consuming and labor-intensive job. I recommend having a technician check the high and low pressures with gauges first; that's the most accurate method.
The air conditioner not cooling properly could be due to these reasons, I encountered this issue once last year. The most common cause is insufficient refrigerant - those rubber joints on the AC lines tend to develop leaks over time, especially noticeable in vehicles over five or six years old. A non-functioning compressor is also troublesome; if that metal canister with the pulley in the engine bay fails, recharging refrigerant won't help. Another often-overlooked detail is a dirty cabin air filter - reduced airflow from vents can mistakenly make you think the AC isn't working. My neighbor's car had a burned-out blower motor resistor causing uneven airflow. The most frustrating issue is a faulty temperature sensor - it keeps cooling excessively even when the temperature is adequate, eventually causing ice buildup that blocks the vents. I recommend first cleaning the condenser during car washes - sometimes clogged radiator fins from cottonwood fluff can cause this. If that doesn't work, it's best to have it professionally diagnosed.
