I've been in the rabbit hole for a while without finding the egg. I have a 98' F150 and the left/drivers side door lock switch locks and unlocks the right/passenger side door lock but not the left/drivers side door lock. The right/passenger side door lock switch only locks and unlocks the passenger side door.
I have found no one else listing this situation. I think the problem is the left/drivers side door lock actuator. Can anyone please confirm this?
Thanks in advance!

 

I have the same issue on my 2000 F150. I can hear my actuator click when I hit the switch but it doesn't unlock, so you aren't alone but I haven't found a solution yet, but I believe, at least in my case, it may just be some type of linkage needing adjustment.

 

I do not seem to hear a thing on the left/drivers side, only the right/passenger side.

 

Just guessing that yours is the actuator itself or lose connection somewhere in the door then.

 

I like the positive thinking of a loose connection. No cost, only time. As long as I don't tear it up.

 

actuators get weak/ wear overtime and will not properly stroke the linkage. Some have a built in resistor that can crap out and then no current flow.. Solution is to replace the actuator.

 

Thanks to everyone for your feedback! I will be tearing it up soon.