I'm glad to have come across this rather old posting. For many years now, once or twice a season I would have a minor driver's side power window issue. It would either refuse to go up and/or down. I would just pop out the switch and toy with it until it began working again. Usually it took one shot and I was good to go for the rest of the year. As luck would have it, last October the day I was to store her, the window refused to come down. Just today I decided to check and see if there was a fix for this intermittent problem. That's when I ran across this thread.
I pulled the switch apart, and frankly, it was pretty clean inside. There was some dust and hair that had somehow got lodged in there, so I cleaned that out, wiped down all contact areas with some WD-40 and put it back together. What a mess though, with all that black grease GM applied in and around the switch. In any case, the window now works. However, when the switch makes contact now, I notice a spark which you can see and also hear as well. It's a little puzzling as I don't think the power windows themselves have a separate ground for them. I wonder if that black grease (which happened to get squished around) is a form of conductor? I may have inadvertently had some of the grease hit two pins at once.
