Hope this helps....
Door ajar switches mount at the rear, perpendicular to the striker. Should be single lead switches. big problem with them is making sure that they are grounded. power comes through the blue wire that connects through the low fuel relay harness and overhead console harness. i think the power comes from the low fuel harness black wire that connects into the tan 3-female power line.
low fuel challenge is to splice it into the fuel gage wire. i wound up lengthening the wire, and splicing it into the 8 pin connector down by the emergency brake.
haven't had any issues with the seat belt buzzer yet, but won't be surprised when it does go screwy on me.
if i am off the reservation on this, somebody keep me honest...willing to learn here as well.
thanks,
PHC