National RV Dolphin not charging batteries

map40 wrote:
I have a 36 class A that sometimes it doesn't charge the coach batteries. Even when plugged in, the batteries get low. If I jump them with the engine battery, suddenly everything is OK, even after I take the jumper out, suddenly the 12v charging system works, and the batteries start charging again. Any ideas?

It may be there is a charge relay inline that prevents feed back from the alternator to the converter ;;in line after the converter and its stuck in the alternater charge mode? don't know just a idea
OR if you have a inverter/converter combo system the inverter transfer switch may be failing; I have seen that a few times although I have never seen where jumping batterys rectified that situation