Power windows have become nearly standard on cars of different types all around the world, but they do tend to get stuck or break in certain situations. In your BMW E34, if your window gets stuck, you will not be able to use a door crank to roll it up or down. You can, however, troubleshoot the problem with a few simple steps to manually roll the window up.
Open your door and position yourself at the open end of the door. Place one hand on the outside of the window and the other hand on the inside part of the window. Press against the window with both hands to pull it up manually.
Spray the window and the area around the window with a lubricant such as WD-40 to allow the window to move with less friction. Insert a straw into the bottom of the window and attempt to insert it past the rubber window gasket. Spray the lubricant into the straw to lubricate this unexposed part of the window.
Locate and remove the screws holding in the door trim panel. Once the screws are removed, slide off the panel and remove the plastic liner covering the controls. With this guard removed, check for stuck levers, obstructed rollers or broken gears.
Clean the area underneath the weather guard of any dirt or grime, and dislodge any jams to get the window working again.
