Removed the interior door panel on the right rear door and found 2 unused wires: light blue and dark blue, with a black harness on them. Wires were about 12" long and taped near the bottom of the door.
Any idea what they're for?
They aren't for the license plate light, door locks, or interior light controls and there's o defroster wires in the glass and I doubt backup cameras were an option in '97.
I'm the original owner. Removed the panel to install a backup camera, which didn't work because the license plate, centered in the door, is too far off center to view the trailer hitch. I returned the license plate mount camera and ordered an iBall with magnetic mount and NO wiring for camera or display.

 

Those wires sound like they're for speakers. The Express vans that I've had, the rear speakers are mounted above the doors, but I've seen earlier Expresses that have the speakers mounted in the rear doors. According to the wire diagram light blue and dark blue are for the right rear speaker and brown and yellow are the left rear. I'll bet that's what they're for.

 

Thanks - I never thought of speakers. It's a conversion van and has rear speakers, but not in the rear doors.