I had that recently. I changed out the lock mechanism and still had the same problem. Turned out to be a broken wire in the loom from the door to the body.
If it happens to be the lock actuator, it's one piece with lock mechanism. Not separate, at least on my car it was.
Ok... I would get back there and look around but the vapor shield (that plastic stuff) do I pull it back or what?
Representing all the N/A out there. Fastest stock N/A you will ever come across.