After reading some of the recent posts, it would seem that I am not alone with rear window challenges.

Problem is that the window motor will drive the window up but not down. I have removed window assembly so as to lubricate. I reassembled all without the glass and when I apply power to the motor, the arms go up. When I change the key direction, the arms do not go down. The motor does not reverse. Any suggestions?
Thanks in advance.