It sounds like the ac compressor or the clutch, if you don't know how to change any a part off the ac system I would advice to 1)get a Haynes manual and read up on it or 2)go to a reputable mechanic and have them change whatever part is broken. If you plan on working on the ac system I would strongly advice to be careful when draining the freon out of the system and then flush the system out so there's no debri that can clog it up.
[B][COLOR=Navy]00 WJ I6 4.0L 4x4,
FIPK Gen2,Borla Exhaust Magnaflow tip, Carsound Cat, 62mm TB,Alarm/Remote start,Tinted windows,Front and rear tow hooks,Hypertech programmer3. Addco rear and front sway bar, Hid's 8500k[/COLOR][/B]