[DebNJim B]

Jamier2.
Just caught the renewal of this thread. It has been a couple of days since your last post so all may be remedied by now, but if not here's my thought. There has to be a place where the 1/2" pex tubing changes to the 1/4" tubing that feeds the ice maker. That is where you will find the second shutoff. Once I found ours I left it on. I don't winterize because we live in our rig in the winter and store it in the summer, but if I did need to drain that line I would just still leave that second valve open and shut if off under the sink and open the low point valve.
Hope by now you're getting lot's of ice.