When the outside air temperature is in the 20's or lower, some of the door locks on my 2000 Ford Taurus don't move - so you cannot lock or unlock the car. The power door lock actuator energizes, and you hear the familiar clunk of a lock being turned, but the lock doesn't actually move. Pushing or pulling on the lock manually doesn't get the lock to move, either.
Any ideas what causes this problem, and how to resolve it? Thanks in advance for the help.