You blew a fuse (I think)...
I did the same thing, except i shorted my domelight, which in turn killed the speedo and wipers. Granted, this was on my 2002, but, based on the two manuals, they aren't that far off... look in your manual and look up the fuse and check and see if its toast. Should just be a mini 10 fuse AFAIK.
Edit: Looked up the fuse in my old 2000 manual, check fuse #26, not sure if that is it, but it could be.
If it isn't this, your wiper relay should be the first one, but since you have the 5.0 swap idk if its the same.
Though just glancing at the fuse list, there isn't any fuse that the seats should effect, but you could have hit something else too, not sure. Maybe someone else might check in and offer some more guidance.
Good Luck