Originally Posted by Ford1
One other note. If the coach batteries are too low, the Disconnect Relay will not be able to pick up. That will prevent the converter from charging the batteries. The best thing to do is put an automotive battery charger on the batteries to get their voltage back to normal, then the relay will activate allowing the converter to maintain the charge.
Yep, doesn't cost anything to try it. Throw a DVM on the house batteries and see what the charge is. Plug it in and see if comes to life. If so, keep charging. If not, throw a good car battery charger on it (I have a smart charger that is 2/5/10/30amp and I set it to deep cycle and let it manage the charge. The batteries should come back fine, as long as they're not long in the tooth.