Ac starts blowing warm air before dash lights & gauges stop working.

What is your question?

Its a 1998 chrysler t & c lxi. After a couple restarts all lights except service engine light goes off. So I take to mechanic and he resets something and it goes off. Lasts about 2 weeks each time. I also have to recalibrate ac system. Any ideas? Will it be expensive to fix?