I had this problem with a 98 windstar. I disconnect sensor in my slidding door. Check below the steering (right side). You will see a connector. All door switch go here and you will be able to check witch door is defective (close all door for make your test). All door put signal to ground. Now this is the color:
Left door handle sw Wht/LT Blue
Right door handle sw Wht/LT blue (left & right go to the same pin)
Left door ajar sw Blk/Yel
Right door handle sw Blk/pnk
Slidding door ajar sw Blk/Wht
Left liftgate ajar sw Blk/LT Blue
Right liftgate ajar sw Blk/LT Blue (Left & Right same wire)
Reference: Haynes manual
Wish I help you
Bye | 
