Here's quick instructions of how the wiring diagram works when installing a power door lock kit like this:
into a two-door Ranger that originally has the manual door locks. The kit only came with these instructions:
so I wanna help a little bit.
Basically ignore the white and brown wires completely, unless your truck also has the power lock button, something like this:
The white and brown wires serve no purpose without that lock button, so cut them off, tape them up securely, and get them out of the way. Their original purpose is to send a quick pulse that unlocks when white is grounded, or locks when brown is grounded, which would be controlled by the door lock button.
Without the white and brown wires connected to the driver door actuator, there is no need to ground the actuator with the black wire so you can snip that one too. The central brain unit does still need to be grounded though.
Let me know if there's any problems with any part of the installation and I'll be happy to offer my input.