Just wanted to share an upgrade I did to my first gen expedition before I sold it that was really nice to have. The 2nd Gen Navigator seats are a direct bolt-in and not that hard to wire up, but you do need to know know to splice some wires. I can only imagine 1st gen Navigator seats will work too, but I think the 2nd gens are more comfortable. When you get the seats try and get the connector for it and about 3-4" of wiring from it to make it easier. I don't have the schematics, but there are 2 hot wires and 2 gnds you have to hook up for the power seats to work. I never tried to get the seat cooler/heater working, but I'm sure it wouldn't be that hard. It's just a matter of adding the switches somewhere for it that you would have to figure out.
The fuse amp requirements for both the seat heater/cooler and motors are higher than the one 20A fuse (I believe the Navigator has 2 seperate power wires) for it normally so you could either run another wire, only use one function at a time (move seat or cool/heat seat), or try your luck and see if it doesn't burn out the fuse.
The fuse amp requirements for both the seat heater/cooler and motors are higher than the one 20A fuse (I believe the Navigator has 2 seperate power wires) for it normally so you could either run another wire, only use one function at a time (move seat or cool/heat seat), or try your luck and see if it doesn't burn out the fuse.