Some, most?, with the Progessive Dynamic converter are wired to charge while the disconnect is off.
Whether it would blow the reverse polarity fuses with the disconnect off is unknown by me, but it seems plausible because if the disconnect was off you could still hook the battery up backwards and send a reverse polarity back direct to the converter
Thought I'd through it out there.
Sure sounds like it though if the electric jack is still working.
2016 North Point 341RLTS
2012 F-350 Lariat CC SRW