1984 345 Motorhome.
2 Furnaces, and 2 Roof AC units.
Rear furnace Thermotsat is faulty, and switches furnace on at random, draining the batteries.
Pic of old unit:
Did some research and found the ModmyRV site and article on upgrading to a Hunter Digital Thermostat, here
Bought the same unit, and looked at the Owners and Install Manual here
Issue is that upon removing the old Thermostat, I find only 2 wires... Both the same color!
The Hunter Manual says for a 2 wire heat only system, connect one wire to Terminal W(Heat relay or valve), and the other wire to Rh, then Bridge Rh and Rc.
My concern is how do I know which wire to connect where?
Should there be 12v
Also, a more complex question, is it possible to wire our older systems with rooftop AC into the Thermostat?