skifast

36 minutes ago, GlennWest said:

There is a plugin your thermostat that as no power and makes continuity when it call's for furnace. 

what I am looking for; does the thermostat send a current to activate a relay to close the furnace wire loop or does the thermostat just close the loop?  

If I am correct, you say "continuity" to close the loop, right

In this case it's just splicing two connections, in the first case it is adding a simple NO SS relay, I think

8 hours ago, GlennWest said:

You can use ohm meter to find out. All furnace use is two wires. Beaks circuit only. Put both end together and furnace runs. 

ohm meter to wires coming from the comfort control center?

I have a Dometic Comfort Control Center, 10 button which operates the Atwood propane furnace and a Dometic Penguin Roof AC.  I intend to replace the AC with another product that is self-contained and operation is Bluetooth controlled. So we have some unused wires, 12V +/-, control wires from the thermostat control center and two blue wires going to the furnace. 

The furnace was obviously controlled through the Dometic AC control box. What wires would I connect to get the furnace working with the existing 10 button Dometic control center?