Sorry, I don't have a real answer, but I did discover last weekend that just because a fuse was labeled "DS" doesn't mean it actually goes there.
We had 3 mis-labeled breakers and fuses on our panel (maybe more, but haven't explored it all yet).
Does the Battery Master disconnect kill it? I understand that the Propane sniffer and possibly the backup camera, if you have one, are hard-wired to the battery so maybe they cross-wired something there.
Sorry to be so little help. but we're real new at this too