Tom, I think you may be on the right path. If you have 12 volts working when plugged in or the gen is running, the converter is supplying the 12 volt power. If you have 6 volt batteries for the house, it could be a bad connect between them, or a problem with one of the batteries. Start with the house batteries and verify you have the required voltages total and between them. Then work out from there. There are a number of different isolation/disconnect circuits on MHs. Try www.intellitec.com website for instructions on trouble shooting and actual circuits. Good luck
