Lenr:
Well....I called Dometic directly. For my application: upgrading my dometic duo therm analog t-stat to digital, CANNOT BE DONE simply by switching out the t-stat. Which, I was hoping was not the case. Simply because look where the a/c unit is? On the ceiling in your coach! And.....the control box (an approx. 5" X 5" X 2" silver metal box) has to be replaced as well. So I need a Dometic replacement Kit: a digital white thermostat that illuminates etc. and the control box. Prices vary from Sellers from $77.44 (which I'm ordering from rvpartscountry.com) up to over $100.
A decent DIY'er, I learned from Dometic that I'm going Analog to Digital aka Single Zone. So on my current Dometic analog I have six (6) incoming lines. I'm now only using 3 and burying the other 3. As far as the control box in the a/c unit on my ceiling, until I receive the replace control box, I'm please God hoping it's a simple disconnect and replace the old wires to the new, PERIOD.