On a girlfriends WJ I swapped the broken manual with a power seat and did a quick wiring job. It was a heated seat with memory and a huge wiring harness unfortunately I just cut the harness out of the carpet in the junk yard when I pulled it. I figured her Jeep would have the harness under the carpet. My mistake, no harness.
To get her up and running. I bought one of those 20A fuse doubler things. I can't remember which fuse I used at the fuse block but i think it was unswitched and something that I didn't think would be on at the same time as she adjusted the seat. I found a pin out diagram for the harness. I figured which was the main power wire and ran it under the carpet to the fuse at the fuseblock and ran a ground from the seat harness to an existing ground point under the carpet.
It worked great. now if I ever go back to the junkyard I'll look for a wiring harness and switches/bezel for the heated seats.
94 ZJ,4.0, AX15, NP231