Re: Danhard 12V
This sounds more like a star cool than the newer Danhard system. I have the Danhard and it is thermostat controlled and separate from furnace. The ones we refer to as Danhard started getting installed in 2008 I believe. (however, to confuse things, I think the star cools were also partially mad by Danhard. One of the many people on here with the star cool systems should be able to answer your questions.
Pueblo Gold Ford EB 350 v10 with EB 50 floor plan & Quigley 4x4 from Huntington (aka: Minerva)