window motor help please
 

I pulled out my passenger window motor today to try and clean it, since the window is very slow while going up. Now I can't get the motor to turn. I have power at the motor, and at the brushes. When the coil part is connected to the brushes, it magnetizes, but when I put the cover with the magnets in it on, it won't turn.

Does anyone have an idea what is going on?

Thanks.