There's a (probably not too useful) pic on page B.1 (pic B.P1) of the owner's manual showing the area
under one of the swivel captain's chairs. There's also a schematic of the entire electrical system for the
'02 190P in the same document, section E page 5. If you can't get an online PDF copy from here, there's
one available at the Official Roadtrek site.
I have a Chevy '02 190P myself. If I can help with what you're looking for any further, let me know.
If you're not in a hurry, you could ask firstname.lastname@example.org
. They may have pics for the specific area
you need. Just send them a note and include your VIN with it. They're pretty good.