Blowing air and making it cold are two totally different things. The fan blows the air in. The heater/ventilating/air conditioning system, (HVAC), is responsible for making that air hot or cold. You will find the air still can get hot when you turn the heater on. The compressor is just one part of many in the AC system that makes the air cold.
My concern is if you added refrigerant in the past, how did you know when the system was full? The AC system works on the principle of a liquid becoming very cold where it turns to a vapor. If there is too much refrigerant in the system, or too little, the liquid will be turning to a vapor under the hood, not inside the dash where it is supposed to do that. Also, over-charging the system can be a lot more harmful than an under-charge. If there is too much liquid, it can slosh out and get into the compressor and damage it. Compressors can only pump a vapor, never a liquid.
If you over-charged the system, the air coming into the car will not be very cold. Or, if the system is under-charged due to a leak, you will also get warm air. That leak must be located and repaired to prevent the repeated loss of refrigerant. Unfortunately, there is no easy way to know how much refrigerant is in the system other than to recover what is in there, then pump in the exact measured amount. Only older Chrysler products had a sight glass to let you see when the system was properly-charged.
As for the compressor diagnosis, that is not the most common cause of the system to stop working, but I have no reason to second-guess the mechanic. If an internal valve is broken, it will stop pumping the refrigerant, and you will have warm air. They also have a seal at the front. If that starts to leak, the loss of refrigerant will also result in warm air.
Sunday, August 20th, 2017 AT 4:41 PM