hope your selector valve cycling fixed it. I had a similar problem on first use after winterizing. Used the valve in the winterize position, put trailer to bed. On next use we were on our way to Florida, first stop....hooked up to city water and none got inside, valve was set to city, after cycling the valve 180 degrees it now works for city water in but points to the wrong source (directly down and not labeled). Probably will get new valve now that I read Jim's post.
Gary.