Mine did the same thing but upon investigation the squirrels tried to make a nest under the hood and while doing so chewed my vacuum line in two. (My truck sits a lot when I'm on the road)

I can hear and feel it clicking in the vsm when I hit the switch so I know there's power but it does not move the locks. I've seen where some say it may be the actuators but I can't imagine all 4 going bad at one time.

My electric door lock all quit at one time. I've heard it might be the VSM. Can these only be bought from ford?