As many of you have stated when you first began dealing with an a/s, its always something new. I did as suggested and looked under the bed and ther was nothing there but heater hoses and storage trays. 1st lesson, make sure you tell the floor plan of your coach when looking for help. But the valve hint did put me on the right track. When the coach was winterized all drain valves were left open (is that the right way?) I finally found the two valves in the back right corner of the coach, directly above the "leak". The access hole was a very small opening below the vacuum cleaner. Reach in, closed the valves, no more "leak" and one to the next problem.
Thanks for the advice, great thread, great help. Glad to be a member.