Is the wiring for a 1998 Dodge Ram 5.9 the same for a 2001 Dodge Ram 5.9?

Answer 1

For the most part yes.  If they have the same options and accessories then yes.  Obviously a Base model Ram with manual windows, two wheel drive, won't have as much as a Laramie Ram with power everything, 4 wheel drive, and a ceiling mounted information center.  But if the options lists are the same, so is the wiring.