I have done a lot of reading, but there are a lot of AC problems and I have not hit the exact one I am having. I do know I have some vacuum problems, because the 2 center vents are not opening.

I don't think vacuum would cause the problem I am having. First off I had a friend recharge my system and no cool air was coming out. He noticed that the compressor was unplugged. Well we plugged it back in and then we started getting cool air out of the outside vents. After a while though the compressor made a heck of a noise (released gas). What we noticed is that the compressor was on all the time it would not shut off until we unplugged it which is probably why it was unplugged to begin with.

What would cause the compressor to be on all the time? Where should I start the trouble shooting process?