I have just purchased a 2010 Road Warrior 305, with dual 6 volt batteries and they aren't charging when the generator is running. I have 110 volts at my plugs in the trailer so I know that's working and when I plug it into the shore line the lights on the panel all come on, indicating its charging that way, I've checked for fuses and breakers on the panel, pulled it out and looked behind it but can't find any other fuses, do you have any ideas where I should look next?