2005 Ford Mustang • 86,000 miles

I own a 2005 ford mustang v6 basic model and the windows are the type that have to roll down to open the door, they do this automatically. Well mine have started to malfunction upon the shutting of the door they dont go down, and if the door is open they seem to have a seizure going up and down in that little increment of two inches like it cant figure out to go up or down. And I noticed if I fiddle with the door lock actuator part where the door lock catches it will sometimes straighten up a little and go down to shut the door, what needs replacing here? Whats the part called?
February 15, 2013.

Have you checked the wiring to the switch? It sounds like you have a broken power supply. Check between the door and the door frame as well as in the door itself.