tailight fuse number 1996 ford windstar?

Answer 1

look in your owners manual :)

Answer 2

If you don't have the owner's manual or a repair manual, remove and observe and replace all of them, and exchange the one(s) you find "popped". It is easy to tell which are burned.
If you have a "Test light", use it to check them. All of the plastic fuses have a metal tab at the top of the fuse to test them, but your lights must be ON to check them.

Good Luck