climate control problem

I'm tring to fix my mothers climate control, she has a 99' montana. when you try to push the recirculate button, it doesn't work (works sometimes) its mostly on fresh air, also speed 1&2 doesn't work, only 3,4,5. the rear fan does the same thing, it won't work on 1&2. i checked the fuses and nothing was blow, does anything have any ideas what it could be? maybe the harness is partly unhooked? also is there anyway to pull airbag codes without haveing a reader? or going to a dealer?
thanks for the help