I have a Monaco Windsor, so might not be the same BUT
In my passenger side rear run bay I have a fuse labeled DUVAC, check the fuse.
Back by my alternator I have 2 fuse holders, one 5 amp fuse is for the Alt Fail circuit, there is a 5 amp fuse for the Ignition.
2002 Monaco Windsor 38 PKD Cummins ISC 350 8.3L
2005 Jeep Grand Cherokee w/5.7 Hemi