First, verify that each battery is a 12VDC battery. I "ASSUMED" mine were 12V batteries when I first got the coach and bought 2 new 12V batteries to replace them.....WRONG...they were 6VDC batteries wired in series to produce 12V with higher current, and I came really close to overloading the entire coach electrical system when I hooked the 2 NEW 12V batteries in series. DOH! Now, I run everything off one of the 12V house batteries and haven't had a problem.
Once you verify that each battery is supposed to be either 6VDC or 12VDC, you can verify if they are good batteries or not. I suspect they are bad and once you replace them with a good set, everything will go back to working properly.
