Chrysler Repair: 1999 chrysler 300m, auto air conditioning, heater coils

Question
hello, i appreciate the time you take out to help answer my question as I cannot seem to find an answer.  I bought my chrysler 300 a couple of years ago, however, last year, my air conditioner slowly began to stop working.  when it is cooler outside, and i turn my a/c on, then it blows cooler air...however, when it's hot out, it blows hot, hot air!! it's almost as if it is blowing the air from the outside into my car.  my heater works fine..the fan works fine..but the ice cold air i use to get no longer exists.  what kind of problem does this sound like to you or have you had the experience of dealing with in the 1999 chrysler 300m model? please let me know. thank you in advance

Answer
Hi Tyonna,
The most common reason for this behavior is a gradual leakage of refrigerant from the system to the point where a low pressure safety cutout switch inhibits the clutch action necessary to connect the AC compressor to the engine. The remedy if that is the case is to have an auto air conditioning repair shop add refrigerant to the system. So that would be the first order of business and it usually is the answer. Beyond that would be to ascertain whether the compressor is indeed being brought into action by the clutch, once the refrigerant is up to standard as regards amount in the system, should you not then get cooling. There are self-diagnositic capabilities in the control panel should that be the case. The temperature of the output air is determined by mixing air from the outside that has passed through the heater coils with air from the outside that has passed through the cooling coils, in a ratio that produces the desired temperature. The door that controls the mix may not be responding properly to commands so that might be noticed by the control panel and denoted as a fault code via a self-diagnostic test. But again, I would believe that the refrigerant level question is the first one to answer.
Roland