Thanks Fred. I think that is it. I did buy two conversion boxes, one for each AC unit. Those were replacement circuit boards like you mentioned. From what you are saying, I probably need to buy a third conversion box to replace that old unit, if I can find it. In the Dometic material I read that each odd zone needs a dedicated 12V power supply. I wonder if that is something that will already be there or if I need to buy something for that too. Thank you for the info. That clears it up for me. If anyone knows where that third zone box is located, please let us know.
If I decide to run a new thermostat to the bathroom, it seems like it may be hard to find a route to the bay containing the Hurricane. That seems to be in a sealed bay and I don't see an obvious pass through to get from the bathroom to the Hurricane bay. If that proves to be easier than I think it may be, that could be a more simple solution.