OK, did some more searching this AM. Crawled under the trailer and found a junction box. Opened it up and lo and behold a 30amp fuse. Pulled the fuse and checked, and the D#$% thing still works. This is with shore power disconnected, battery disconnected from coach with switch. All fuses in panel removed.
Two issues now - where does the slide get it's power from (has to be direct from battery somehow) and what the heck is that other 30amp fuse for? The only other thing that might draw 30 amps is the tongue jack and that is wired direct to the battery.
I think I'll try Mex's suggestion next.