I was trying to mirror the 2x sub fascia on the end of the roof trusses from right side to left.
select object
first mirror point at peak of roof, second mirror point vertically on blue axis and third out on red axis.
UPDATE
I copy / pasted my model into a new file and now it works. Must have been a corrupted file. I did have a system crash at one point while working in the original file Also, the original file was the last of many Save Copy As versions as I explored different options for a garage.
Thanks for your comments.