SL350 passenger rear window not working

[tariq jahan]

Hi guys have an SL350 problem started last year. Had the roof down when i got home and went to put the roof up the passenger rear quarter window would not go down so the roof would not close after trying a few things i gave up and went inside to see if i could find anything on the internet half hour later not finding anything went back out started the car it started working. To cut it short its come back and window wont go down and the roof wont open any advise would be appreciated thanks.
ps its been over a week still nothing.

 

[RAJ55]

pretty common problem, either a weak window motor or the felt lining on the internal window rubber has worn and is now catching