I agree with John. I had the exact same symptoms in my 98 XC (about 90,000 miles at the time) - rear windows would not work. Then, we noticed an electrical burning smell when using the driver's window, and all the windows quit. The nasty acrid smell came from the driver's switchpack.

Bought a new switchpack on eBay for about $80 or so. Popped the old one out (just stuck small screwdrivers around the edge and popped it out. I didn't remove the door panel. While I made a few marks in the plastic bezel around the switchpack, it was a very simple replacement, and I would definitely do it the same way again). Pulling the old unit apart, I found how the internal contacts had worn out and could see where the current was arcing, causing lots of black stuff and a bad smell.

I think the dealer wanted $150 or so for the part.

Good luck.