[Saurian]

Assuming the compressor is OK, check the tension on the belt. Usually after I have replaced/serviced my serpentine, I will test it at full load; all electrical on and on high for maximum resistance at the alternator, air conditioning on for resistance at the compressor, and hit the gas a couple of times... If it's going to squeal, it should do it then. Hopefully, it should just be a loose belt, which would explain the lack of cold if it's slipping on the compressor instead of driving it...

A more expensive option would be the compressor bearing, or the clutch... Start with the belt, hope for the best, welcome to Jeepz, good luck with the rest :)