Yesterday, I had a duh - AHA experience. Our A/C is making an intermittet noise. A screeching, if you will. Fan? Motor? Intermittent?
If it's not making the noise all the time, how can a repair person (Oh, how very PC) tell what is wrong? So we waited. Then realization struck. While the screeching made itself audible, I switched the unit to "Fan Only." Screeching kept right on happening.
Calling the lucky repairman this morning with our pinpoint diagnosis. Heh . . .