left rear window stops half way down

The left (driver side) rear window on the 1999 Suburban has decided not to roll all the way down anymore. It will go up and down at normal speed but stops like there's a block in the way. So motor is working, switch is working. Just stops a little less than half way and thats it.

I'm wondering if there is a position sensor or mechanism i.e. the thingy that tells the motor when to stop based on the relative position of the window? Is there a way to recalibrate?

Thanks

Ketch

Time to pull apart the door panel and inspect for any broken or binding parts. Lubricate the tracks with white lithium grease and silicone while your in there and see if you can bring it down manually.

My 99 did the same thing on the rear passenger side window.
It was the lock actuator. The pop rivets had broken loose and the window would run into the acutator on the way down.
I didn't have a pop rivet tool, so I just found some small nuts & bolts in the garage and drilled out the old pop rivets and bolted the lock actuator back into place. Window works like a champ!