Magnum 2012 Inverter
Magnum ME-2012 2,000-watt 12VDC/120VAC off grid Inverter
I have to say this sounds like an awesome Inverter/battery charger! (except for the part where it is not working now
).
It sounds like the fuse between the battery and the Inverter/Charger has blown.
If you have the one I am thinking of, it can be reset by pushing the little button on the side of the fuse.
The indicator light on the RV just shows the voltage present in the distribution panel and NOT the voltage AT the house battery (which is most likely dead at this point).