Trailer lights connection
I have a 98 and I did this back in 98.
I purchase a short pigtail from Ford ($14 I think)that ended in a flat 4 connector. It connected inside the rear where the jack is stored. Then went out a plug hole, the kit had the grommit to re-seal the hole. THe kit also had a mount for the 4 pin connector.
It was a cheap, easy, 10 min job.