Window question

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Is there something in the tracks that's preventing the slide from going all the way down. I've had the square plastic guide slide to the bottom of the track when I unbolt the window and it's about 1-1/2" square.  Just a thought. Is there a bolt sticking out blocking the horizontal slide. I, like others have said am not able to think what it is without actually seeing it. I've been out in my shop looking at the spare regulators and tracks I have and can't figure out what it could be. Sorry. Just a though; if a friend nearby as an e-body, buy him lunch if he'll pull off his door panel and let you compare the difference between your window and his.

Terry