Same here,, 2005 classic and there is a 1 amp glass fuse on the buss bar.. I take it apart when in storage to help not kill the batteries so i am more than likely sure there is a fuse somewhere. the 5-7 yrs is powered on the whole time. If you pull fuse when in storage (some 6 months a year) I would suspect something close to 10 yrs but that is my opinion of course.
Carl, Raleigh NC
2-24-16 got a 2005 Classic 31D
TUG2.net check it out for good rental deals
2003 F-250 SD, CC, 7.3L PowerStroke
, Piedmont Airstream Club
, Unit #161, Region #3