A lot of the time, a seat problem like you have turns out to be the switches. You can clean them either with a good spray like CRC contact cleanr, possibly WD40, or take apart and manually clean with eraser.

 

Good call on the switch for the seat, corrosion and dirty contacts. I had to tweak a few because of wear but all functions now. Of course it took me 3 trys to get it all assembled correctly, learning experience. Here's a fun fact, you can use a LH window motor on the RH side. Requires a little adaptation.