I was driving in my 2012 Volvo XC90 when my driver side, passenger window just started slowly rolling down. The window button on that door, nor the one on the driver master window button panel could stop it from slowly rolling down. It eventually got all the way to the bottom by the end of my 5 min drive. By pressing that windows button it puts it in almost a free spool and I was able to shimmy it up almost all the way and duct tape it. Occasionally I can hear the window motor activating and running but the window just stays there. What’s the cause and how do I fix it?
Test your window switches, check grounds, and look for chafed wiring that might be feeding unwanted voltage to the window regulator motor.
Make sure your battery and alternator are up to snuff since computer modules don't like low voltage or excess ripple and your windows are most likely controlled by a body module. (Hopefully the problem is not being caused by your body module going funny in the head due to internal failure. You'd need a professional-grade bidirectional scan tool to diagnose that.)
You can find a repair manual for your car at the link below:
