AC Compressor issue
 

I tried my ac for the first time today in a couple years. The compressor seems to lock up. Is the compressor shot because the car's been sitting for so long? Any work arounds?

I think if the freon in the unit is fairly nonexistant then it prevents the compressor from operating in a normal fashion. Might be your problem.

The pressure switch prevents the compressor from spinning if there's too little refrigerant in the system.

When you say "lock up" Does the whole pulley freeze up or does the compressor just not kick on?