Think I figured it out. First thing the internal temp fan had broken pieces in it. Removed them. Still cold air. Then I went to the valve and unplugged the hose that goes to the core just to see if the valve was working and had hot water coming out. It was. Hooked it back up and tested the heat again in auto. Bingo hot air again. Not sure why I had to “prime” the valve but it works now. I think. I will update again when I get on the road.