93 dohc seatbelt lights

The seatbelt dash indicator lights are suddenly not coming on
anymore and am wondering if anyone might have a first best guess
as to getting them to work again. The fuse for this lamp/light
appears to also control the 'chime' and some other stuff which
is all still working. Kind of narrows it down to the dash
seatbelt indicator light bulb itself or some switch somewhere
in the car. The Haynes book didn't have much about it that I
could readily find so thought I'd ask here.

Is there something within the seats to trigger this seatbelt
dash indicator light? Are both front seats supposed to work the
same as to light up when a passenger has not buckled up?

I did replace, today, a front side marker light socket that I
got from a junkyard. Saturn dealer wanted $31.45 for the little
plastic socket. Criminal. The junkyard was a little better but
not by as much as I'd have liked. Getting vicious out here. The
socket was full of mud and crud and totally corroded inside.

Thanks, I hope.........,