I was just about to replace the window regulator in my 2000 Blazer (left front) when I came upon this forum. I noticed one of the rivets on the assembly was loose. When I pried it back into position, everything worked. So I drilled out the rivet, added a bolt/nut combo and it works fine.

When the window goes up, it torques the assembly out of alignment when the rivets are loose. The motor can't turn the geared flange until it's back in alignment. Try this before you buy a new regulator or motor!

 

My window knows when it's raining or freezing, and that's when it refuses to go up! For me, I pry up the window switch panel(it's easy, go to the front of the door, and just lift up with your fingertips). This usually wiggles the wires enough to make it work again.

Hey, it's not a permanent fix, but my window only sticks down, about every 2-3 months, so I can deal with this fix for now. My rule - if it's raining or freezing cold, JUST DON'T DO IT!!!