Is your wfco converter and D.C. Fuse panel in the same location ?
Did you leave some wires disconnected from each other ?
Like multiple positive or negative wires that were connected at the battery posts
My converter is stand alone deck mount, in one compartment, my fuses are in the bedroom cabinet, my batteries on the other side of the RV from the converter
If I removed the batteries, I would have to connect all the negative wires, tape them up , and do the same for all the positive wires
Or I would not have any power in my RV