Does it go down by itself (meaning without hitting the switch) when hitting a bump? Or will the switch bring the window up/down after hitting a bump. It'd be good to know this. If the switch works after banging the door or the switch itself, pop off the door panel carefully and check that the connectors are tight/or not rusted/corroded. Assuming you have checked obvious relays/fuses...then its either the switch or the motor itself. In my experience...%95 of the time its the motor...not the switch. Swap the switch from the drivers side and see...or if its easier to try out a junkyard/new switch do that...and eliminate that possibility.
Replacing one of these motors is not THAT bad of a job, but you almost HAVE to by a new one...as junkyard ones are hit or miss. I had an old Corsica that needed one, and the damn thing ran $80! It ususally envolves drilling out the factory rivets holding the motor to the door frame, sliding the arm/motor assembly off of the track of the window...pulling that assembly through the barely large enough hole in the door frame
, taking the arm off of the old motor, put the arm on the new one, and put it all back together.
Let us know how it turns out. Oh...and if you can do this without tearing the $hit out of your hands...you're a better man than I am.
