So, something is definitely awry:
I replaced the battery with an 800 CCA brand new one. Hooked it up and it started right up... instant crank and start up. I thought everything was fine. The next day I went in to start it up and it "seemed" a little lazy on initial start up --- just a very slight hesitation when engaging --- but I thought little of it.
That was about a week or so ago Today I went to start it back up and it's completely, totally dead... nothing.
It has been plugged into a dedicated outlet (20a, 110v) continuously. The only thing running is the refrigerator, which is running on "Auto", which I was told means it is running off the AC current. Nothing else is on in the RV.
Again, just before it died on me, I brought it home from the shop after it being there for 3 weeks getting just some basics done --- fluid changes, replace an idler arm, upgrade the AC to R134, etc. Nothing electrical was done. But the day after I got it back, plugged it into the wall, the battery went dead. Something is sucking the battery dry. I haven't driven it since the day I replaced the battery.
Again, the precursor to all of this was, the day I got it home, I started it up and I heard that "clicking" noise that was diagnosed as being the Battery Isolator Controller.
I talked to the previous owner... they never had an issue with it like this, and nothing electrical. They had it plugged all the time so that the refrigerator would stay engaged so as not to let it go to ruin.
I am totally stumped... any suggestions???