I just went through this exact problem on my '94 georgie boy pursuit. My inverter/charger was only pushing about 11.8V to the batteries, and when measured with a volt meter right on the charger, measured the same voltage. Also, at times the 12 volt accessories would only work when the generator was running. As soon as you unplugged it or shut down the generator, no 12 volts to anything, period. So I started with replacing the inverter/charger with a new one for about $150 on ebay. That did solve the charging problem, now it charges at over 13 volts. But it would still have the problem of not switching over by itself after being unplugged. The problem was these little circuit breakers under the hood. The main power line coming from the inverter to these 3 circuit breakers had 13 volts, but maybe 9-10 volts coming out the other side, and at times 0 volts. These are manual reset, not automatic like all the new stuff is. So I replaced all 3 breakers with automatic ones. Bingo, the thing works perfect now. All my batteries get charged and all the 12V stuff works properly. The breakers were about $4 each and took about 10 minutes to install. These are automatic, so if they get hot, once they cool off they will reset without doing anything. Hope this helps.
