Im a having an issue with my drivers side power window on my 99 f150. The motor that operates the window seems to make an awful grinding or slipping noise when I try to operate the window. I have been trying to find a video for a solution before I get into the door panel. Anyone have any idea what this may be? I've had something replaced years ago when it broke, Im not sure whether it was a switch or motor issue, it was a long time ago. I got it fixed and it worked, unfortunately the switch was wired backwards or something, not sure how. Down went up and up went down. Anyway something isnt right now since it makes an awful noise. It does go down sometimes but is tough to get it back up. Any ideas?

 

Take the door panel off and check it. I would expect that it needs a regulator assembly but open it and see before you buy parts.