just notice my wifes monte carlo's driver power door lock lock working. tried locking with key fob and sounds like it locks but does not. does not lock when put in gear either. tried locking with door switch and same as usung fob. use key in door and it will lock but of course when returning key to pull out it unlocks againg. pulled panel aand all rods connected and no binding, could the be a bad actuator or some other component causing this?