Classic Winnebagos & Vintage RVs

So...I have brand new batteries for the coach. But when not plugged in, I have no power in the coach. My generator or electric steps will not work. I used to be able to play with the Aux battery switch and I can get the generator started and the steps work. When I would hit the aux battery switch, there would be a clicking under the dash. Now there is no clicking and nothing comes on. But even when plugged in, my generator and electric steps do not work.

Is this one of those things that could be a million option to try and fix, or maybe just an easy fix. Only had this motor home for a short time, and I guess I didnt try out everything when I bought it. So hopefully I become an expert and can help others as well. but for now, any ideas???

Your 12v system should work automatically when not plugged in.  Could be an easy fix.
Check your breakers first and any 12v coach fuses.