I had the exact same problem. fan works but whenever i hit ac i just got a hissing sound and no cold. I took it in to midas for a recharge and they told me that the compresssor is bad. ever since the recharge, when i hit the ac button it now makes an awful screeching sound and noticeably drains horsepower. Also there was kinda a burning smell, could it be that the compressor's clutch seized and the belt's slipping? Does getting the system charged put added stress on the compressor?