About how mush would it cost two replace the door lock on driver side

You most likely have a worn out actuator on the driver side door. When you push the unlock button, the actuator is the device that actually moves the lock linkage rod up or down to operate the lock.
The actuator on the driver side door usually fails first because it is used more often than all the other doors. I had to have these replaced on my 2000 Navigator, and they cost me about 250 each to replace (the part is around 80-100 dollars, but the labor is relatively high).

It's called a door lock actuator, and ours was on the driver side, buzzing each time the doors locked. Very annoying. We ordered it online, it was part #4717961AB from a Mopar company. Wasn't very easy to replace ourselves, but do-able if you have at least an hour and two people working on it. Cost us $60 plus shipping.

you may need to replace the door locking actuator, they do tend to go bad over times. does the driver side door lock automatic when using the lock button on the driver side. if you can lock and unlock the driver side door with a switch, my guess would not be the locking actuator, it might be in the remote locking module.

try removing panel and check for loose or worn contacts, or replace the panel cluster with a new unit or one from a junked unit in good condition if cost is a factor

The ford dealership is sure to have them, although other place like NAPA, or Autozone may be able to find you replacement ones for a cheaper price.

inside the door there is an actuator and the rod has become disconnected from actuator to lock mechanism and randomly hits, you have to pull interior door panel and look by door lock inside and look for loose rod and reconnect

This means your door lock cylinder needs to be replaced. It is a 1 hour job and the cylinder costs around $180. Thanks

i had this problem too and it turned out the piece that the door handle attaches to broke. i glued and taped up mine and it works fine now. its worth a look if the WD40 thing doesn't work.

according to my partsman (who has had great advice for many years), you do not have to remove the door panel to replace the door handle which contains the cylinder lock. the handle is released with a screw which you can see when you open the door. you will need a starhead screwdriver or socket. A new handle costs around $40 at a parts store in my area. call around for a locksmith who will re-key your key to the new lock or use the key which comes with the new lock, your choice. i am in dealing with this also

Check inside wiring by the driver's side door hinge. Remove the rubber boot and you will find broken wires. Make a splice and you are fixed!