2002 pontiac grand prix
I'm trying to figure out why the driver side
rear window won't roll up. The regulator
works and rolls the window down but won't
roll the window up
yes well the harness can only stand so much flexing can price one out for you~ not a real easy job, might need a upholstery removal tool~ it's not an easy job https://www.youtube.com/watch?v=qbI65Zq1EaE
Most likely your window motor is getting weak and in need of replacement. No real force on it with lowering the window but more torque is needed to raise the window.
Does it work from the individual switch on that door? If so I'd suspect the driver's master switch is bad. Hope that helps! Jim