You mean "converter". You need the two RP fuses in the converter.
Not clear what the sequence was for the loss of power and the RP fuse being out of place. Did that happen after the several days or later when you took the unit out?
With the battery ok at 12.x volts, you can leave the converter off and just try to run the rig on battery to find the "open". Yes, start at the battery and work along with your meter until you find 12v on one side and nothing on the other side of a connection. (As time2roll always says on these occasions :) )
The open could be along either the pos or neg path. Rain might get to the frame ground by the battery if exposed.