Hi Jindo, if the fan is not working on certain speed settings, the blower motor resistor is a good candidate. I had this issue in my 2000 XJ, and installed a new blower motor resistor myself. It was my first fix of many on that old machine! It was a pretty simple fix to do-- The part was located behind the glove box. If your compressor isn't turning on, that is a different issue, and I'm not sure I'm going to be much help there!
By the way, love the Atlanta Rhythm Section reference for your location. Need to get that AC running for those Dog Days.

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2008 Liberty Sport 4x4 Automatic
Jeepin By Al 4" Lift Kit
BFG KO2’s 245/75R16
Full MOPAR skid plates
Rock Lizard Skink Super Sliders
AtTheHelm Front Recovery System & Roof RackM116A3 Trailer build thread: viewtopic.php?f=72&t=77997