AC turns off and after fooling with controls comes back on. Sounds like a damper is stuck. Can hear a click?
AC spontaneous cut off? on 1999 Cadillac Eldorado
There is a diagnostic code system for your Caddy and you can have some one scan the A/C system for trouble codes and then trace down the problem. This is the best way.
Does the A/C. quit, or the blower motor?