a/c blows hot air what to do on 2000 Mercury Sable

my a/c is blowing hot air and the comperssor is working and it has feron we think it could be a door stuck and not leting cold air in what should we do we cant afford somebody to fix it for us.

2 answers
You could also try and getting a do-it-yourself kit from your local auto part store. It would cost you around $30 the kit should include the hose and a can of R134. Its easy to do for first time users.
Get under the dash and work the controls while watching what the control cables are doing. You should be able to see what's wrong if it's a blend door stuck or a cable come loose.