Pull up your carpet. Look for the rubber tees. Note the red lines for lock and green for unlock. Get a diagram from this website and understand how those lines work. Those actuators are Falsely blamed 99.9% of the time.

The tee connections deteriorate over a period of time.Especially in the winter. Finally replace the master door lock switch. Its a smaller job and also make sure your accumulator tank has agood seal because that deteriorates. You would be surprised, by just pushing and shoving on rubber connectors fixes things a lot of the time.

Check the actuators last as a last resort.