Thanks for pointing me in the right direction. I knew this had to have been previously encountered. I'm going to take a look at the Dometic ducted install kit and also launch a call to Forest River to find out the extent of the factory prep in my XLR. I will use the AC mod relay method as my fall back. All the best to y'all.
I have a non-ducted Dometic AC that was added by the dealer in the bedroom of my 5r. It doesn't have any model #s on it! Hopefully link to photo above will work. Is it possible to add a wall thermostat to this type of unit?