My air conditioning went out this weekend on the hottest day of the year so far. When the Tech checked out the problem, he found that one of those damned lady bugs (that are not really lady bugs) that infest this area every fall got into one of the contacts and shorted it out. I guess they don't conduct electricity very well.
Cost me $77 for the service call but still cheaper and quicker to get it running than I figured it would be.
David