Door lock switch on a Lincoln Aviator will not lock.

Door lock actuator. It's a little geared motor that actuates the door lock from inside the door. Costs about $35 for the actuator, and an hour or two to replace it. Can be a DIY project all you need are basic tools like a screwdriver, a socket set and some sort of flat pry bar to remove the door panel.

The driver door will lock with the passenger lock and the fob. Just not from the driver door switch.

So you're saying the door CAN lock from one of the switches and from the fob? Just not from the driver's door switch? If you've narrowed it down to one switch then troubleshoot that switch.

I did switch is good.