My 91 3004matic air conditioning quit. Compressor not turning. Fuses OK. Blower OK. I do not get air blowing from the middle ducts but do get it on the side ducts. Blows heated air. When I set EC on the control I still get hot air even though it is 55 degrees outside. A couple of days ago I was hearing a noise in the dash area that sounded like a rattle. Pushed the Off button and it stopped. Now no A/C. Any ideas? Thanks in advance.