I posted the following on the Camry forum, but I would imagine the power seats on Toyota trucks are similar to those on the Camry. My 89 PU has a manual seat so this will never happen to it! If someone has the same problem, this may or may not be the fix but it's worth looking into:
The power seat lift motor stopped working on my 2000 Camry. The fore/ aft and recline motors both still work. I tested the switch and it is OK. I put 12V to the lift motor and it still didn't work. I called Toyota to ask how much a lift motor would be. I didn't think it would be too expensive given the size of it, but I got a real surprise. The parts person said that they did not sell any of the motors separately, and the seat assembly would be $1,100.00. I said no thanks, and started thinking about finding one in a junkyard. Then I figured, what the heck, it doesn't work now, how much more can I screw it up? I brought the seat into my workshop and removed the lift motor. I pried up the little tabs holding it together and took it apart. The tiny brushes still looked fine, but I noticed a very dark ring around the armature. I took a pencil eraser and polished it up. I reassembled it and found that it works again! An hour total and I saved a bunch of bucks. Not too bad for a retired person with some time on my hands. Larry D.