How many of us are there? Owners of Dodge based RV's?

Hard to say without more information.

It appears that there is a new white wire going to the fuse panel. What is this for?

Is the refer the original or a newer one. My original doesn't even have a 12v option, so I am guessing there was new wiring needed for your 12v option.

Was the blown fuse for the refer or something else?

When the refer is on 12vdc, it is getting this from the battery which is being charged by the converter which is connected to shorepower (or not).

See, its compilcated.