Ford: 2002 Ford Ranger 4x4 not engaging, switch wiring, ford ranger

Question
When I turn the switch from 4x2 to 4x4, the light does not come on and it will not lock into 4x4.  Someone said it is most probably the control module, does that make sense?

Answer
Hi, well it could be the module, the shift motor, the switch, wiring, or a fuse.

Does the $x$ module communicate with  a scanner?. Are there any codes?

How are the connections at the shift motor?

Shift motors and control modules are both common failures.