Super frustrating AC issue

Just as a final reply for those interested, the AC is up and running. As noted above, I ordered and entire new ceiling piece that has the selector dial and T-Stat dial in it and plan to return the one I had. Ironically, a tech support person finally called me back 2 days after I left a message and email to be called back and after I had bypassed the T-stat. I discussed what I did and he said it still could be either the selector or t-stat, so rather than only replacing the t-stat I pulled down the entire ceiling assembly and replaced with the new. All is running well now and we are good to go with 1 day to spare for our trip.

Thanks again everyone. I will drive myself to exhaustion before I give up trying to fix things, but the replies here were a big help and saved me a lot of extra time.