My power seat has worked intermitantly since I bought the car. I traced this to a faulty thigh support extension switch. Every time I would extend the leg support it would retract a few seconds later. I figured one of the connections was stuck or not being made. When the retract button is being pressed the rest of the power seat is not functional.
Rather than spend $50 from the dealer on a new one I reconditioned the existing one. Here's what I did:
1. pry out the switch assembly with a flathead screw driver
2. pull the switch assembly off the wiring harness, it should come off pretty easy
3. to disassemble the switch I used a kitchen butter knife. gently insert the knife in between the black plastic and the yellow bottom and pull it out enough to get over the tabs. repeat for the other side.
4. when you pull the two sections apart be careful because the metal parts are loose in there. You should find two metal rockers and two ball bearings.
5. clean off all the raised sections where electrical connections are made with a wire brush or just scrape at them with a butter knife like i did. There is some grease on the ball bearings, I just left it alone but you could clean and regrease if you wanted to be thorough.
6. to reassemble place the electrical piece flat on a table. Reposition the two metal rockers, they are different so make sure it's on the right side. Then place the two ball bearings into the valley's created by the rockers.
7. leaving the electrical piece on the table slide the switch back down over it. make sure the switch is in the middle or neutral position so the ball bearings are seated properly
8. Make sure the switch functions mechanically then reconnect in the car and verify it works electrically
Other switches should be similar so hopefully this helps somebody out there.