The Fleetwood Santa Fe is a popup camper. Having owned a similar unit I'm quite sure the thermostat does not control the A/C. They had the usual Atwood mechanical thermostat that have been used virtually forever. As stated above, touch the two wires together and see if the furnace works. If it does, trash the thermostat, and go buy a non-programmable digital one at one of the big box stores. They work much better without the big temperature swings of the stock thermostat. The digital won't fit in the mounting hole of the stock one but a little bit of ingenuity can overcome that.