Scotty, I have an 02 Ford Ranger (119,000 miles 4.0L automatic) and the 4X4 does not work now, it does not light up the 4x4 on the dash at startup either. I replaced the selector switch and the transfer case motor and no change.
Did you check the bulbs in the dash? What about fuses and wiring? Based on my experience with my 1999, the 4×4 lights should come on for a couple seconds when you start the truck, and then go out. The system is engaged and disengaged electronically, and the corresponding light should turn on and off when you select High or Low. If the bulbs are known to be good, then there's potentially a wiring or computer problem.
It is not the bulbs on the dash cluster. It does nothing, I checked all the fuses and they are good. Today I removed the transfer case shift motor and turned the transfer case switch manually and the 4x4 does mechanically work. It just does nothing under normal conditions. I am wondering if the transfer case control module is bad, but I cant find any info on how to test that.
Why the down vote out of curiosity? If those lights are good and they're not turning on for a couple seconds when you start the truck, then that's probably a failure in the computer. They're supposed to cycle on and off to indicate the system is functional, just like the CEL and every other "idiot light" that comes on when you start it up. You may be able to use a scan tool with bidirectional control to try to engage the system through the scan tool.