I had to rework all 4 windows on my Arnage. First check the power to the window. You can do this by unplugging the circular connector at the bottom forward corner of the door. Check for 12V at the appropriate pins when the window switch is pressed up or down. If there is no power you have an electrical problem. If you have power you will need to remove the door panel. There are three possibilities: most common, the window regulator cable has snapped or retainers broken. You can send the assembly away to be rebuilt or buy a new one. Power Window Repair - The Original Power Window Repair Company (If it is just the cable retainer failure you can use a metal one from a bicycle shop). Second, the window has simply jammed in the up position and put the system in a bind. Remove the 3 bolts securing the regulator and try bumping the down switch to relieve the bind. Third, unlikely, the motor has failed. Note that in removing the door panel, as careful as you may be, you will inevitably break some of the red retainer pins. You can order new ones from Flying Spares.