Between my kids and I, we have had a total of six 4 runners, and we currently have 2, a 2002 and a 1995. We have had the rear window issue come up probably 8 or 9 times that I can think of off hand. Two times we had to replace a fuse. Other than that, we have been able to get the window working again by playing around with the placement of the wiper arm. From my personal experience, I would say that breakdowns with the parts that make the window move are fairly uncommon. For us it has tended to be more an issue of not being careful while loading or unloading the back end and accidentally knocking the wiper out of the little holder on which it is supposed to rest. Good luck to you!

I know this question is old, but just in case someone else is having the same issue, I would suggest checking the easiest fix first. Check to make sure that the rear wiper is seated correctly. It is worth taking a few minutes to mess around with it for a bit while trying the window. If the wiper blade is not sitting in its holder correctly, there is nothing you can do to make the window move! Try it. It might save you some time and money.