Without any previous signs of trouble, the A/C went out on me the other day and the heat is really starting to get to me. The fan still blows but that warm air just doesn't do the trick! I would assume that it has something to do with the compressor, but I have never tried to work on the A/C before so I was hoping that someone could point me in the right direction.

Before, when the A/C kicked on, it made a "hissing" sound and then start blowing that wonderful cold air that I miss so much. It no longer makes this sound. What is that sound? Is it possible that it is just low on gas (R-34) and has a low-pressure trip for protection of the compressor? Any help would be much appreciated! Thanks in advance.