Why is there clicking instead of movement when I try to roll down the window?

I've replaced a BUNCH of these - it seems the gear in the motor itself has failed - there are 3 cylindrical, composite material rollers that are supposed to lock the drive gear to the driven gear - they commonly fail .. Here is a link to a YouTube video that shows exac how I've been fixing em for years - it works very well ! It is kinda unusual for a NEW window left motor to fail in this manner - assuming the motor was actually NEW to start with that is. Good luck with it!