The Wipers will move if I help them when I turn them on. I can hear the motor trying to move them. I've removed the arms themselves to see the little spindle thing that the arms are placed on and bolted too, they wont move by themselves either. I have the plastic "cowl", or whatever its called off. I checked the transmission and it doesnt seem loose or anything. I just need to know what I should expect in trying to fix them? Any help would be appreciated.

Its a 1997 f-150 xlt