"Doug. it is the fuse on the unit. the 25 amp. Im as sure as I can be that the batteries are connected correctly. Like I said, we did them one at a time and it was done by an interstate employee. I disconnected the chassis batteries because one was dead/had a dead cell or short and I thought that might be tripping the fuse on the inverter. "
this sounds like the 120v input circuit breaker
not a 12v Dc output fuse
this would handle NOT just the power used for charging, but also the pass thru 120v power going to the outlets powered by the inverter
do you have an electric heater plugged into an outlet that is on the inverter circuit
if so you might be overloading the circuit
30amp main feeding 25amp input on a whole RV inverter, trying to charge and power heaters, too much 120v load