I have a 96 S320 and one of the rear windows wont go down. With the door panel removed I observe the regulator going up and down but it is not connected to the window. With the regulator in the down position the window should just fall down right? Is there some kind of safety thing preventing the window from being able to be puhsed down?

That is simply a window lifter failure.
They are a cable & pulley design.

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