re: AC Repair Companies...who could I get out on a Sunday?

I had a similar issue last year. My outside unit was making a God awful squeal and was getting extremely hot. Took off the cover over the capacitor and wiring. Noticed the capacitor had gone bad (in my case there was this oil/grease looking stuff covering everything). A trip to the store and 40$ later for a new capacitor...cool air and running just fine. It's an easy cheap fix to give a shot.