1995 e320
 

I recently bought a used 1995 e320 with 135,000 kilometres. This is my third week with it and the air condition and heating functions do not work as well as before. I only get a very little warm or cold air. I have noticed that the car runs at the coolant temp around 80 degrees and I seem to remember that it would stay contant at about 100 degrees previously. Is there a connection between the operating temp and the air conditioning/heating?
Thanks for any help. This is my first mercedes and I am hoping to keep it for a very long time. I am told that the 1994/95 models of e320 are among the best from this car manufacturer. I love the ride but am not mechanically inclined.