Hi smallseafishie (love the handle, BTW!). Thanks for responding... I was traveling heavily for the past 6 weeks, so I just now had a chance to look at this again, luckily I have a 2nd vehicle. Too bad it's a supercharged Tacoma with big tires that gets 14MPG!
Anyway, I think you're on to something... I did the battery trick and there was no improvement. So, I popped the seat motor controller out of its little bracket and started moving it around to see if there were some loose wires. Well, I got a repeatable result! If I held it in one specific orientation, the motors worked. Then, if I moved it a little this way or that, the motors stopped moving immediately. There must be a break or short in the harness or connectors.
You seem quite knowledgeable... Would you happen to know how I can get a pinout of the connectors? All the adjustment motors die at once, it must be some key signal that gets interrupted. I think I might just yank out the seat and inspect the harness and connectors more closely.