Your 4x4 module is behind the kick panel in the right front passenger area , beside the passengers right foot , in front of the door. It's just a plastic trim panel.
Behind the passenger side kick panel
The powertrain control module on 1991 and 1992 Ford Explorer is in the right front passenger area behind the right front kick panel
The computer module for the keyless entry system on the 2006 Ford Explorer is behind the rear passenger seat. It is located under the seat belt panel.
On a 2001 Ford Explorer the airbag control module is located behind the passenger side kick panel (located to the right of the passengers right foot if seated in the vehicle).
On 1991 and 1992 Ford Explorer's , the powertrain control module (PCM) is located in the right front passenger area behind the right side kick panel by the passenger's right foot.
On a 1994 Ford Explorer, the computer module is behind the kick panel on the passenger front side.
The 2007 Ford Explorer computer module is located below the dashboard, on the passenger side. The computer module is in a rectangle steel box.
on the module located behind the passenger rear seat under the carpet
The security module on 2002 Ford Explorer is on the passenger side, second row behind the seat belt panel.
The 4x4 control module is located behind the kick panel in the passenger side floor board. The module simply unplugs and you plug the new one in.
Behind the dash...you have to remove your glove compartment door, be careful not to set off the passenger air bag.
I don't know if your Ranger is the same but on the 2001 Ford Explorer the 4X4 module is located behind the right front passenger kick panel