Your 12VDC Converter/Charger is being supplied by the 120VAC from Shore Tie or Generator. When it doesn't have that 120VAC, it isn't connecting your battery to the 12VDC outlets. I hope it's not because you got the polarity reversed, which isn't all that hard to do. Our Jayco has only one Negative Cable to the House Battery, but FOUR to the Positive of the Battery. A couple of those were corroded and not making contact. It'd also be easy to leave one or two of the four off. I taped the four together to form a bundle. The terminals still have to be put on the battery post, but at least I keep them where I can find them all.
