4wd not engaging

[Iffklg]

I own a stock 2003 ford ranger xlt with an auto transmission 4.0v6 and the 4wd has not worked for the past couple years. I decided to try and fix it. The 4wd lights come on momentarily when starting the truck but do not light when the switch is turned. I hear the cm behind the glove box clicking when the switch it turned. I replaced the transfer case motor thinking it was the problem but it still won't engage. With the motor off and hooked up electrically it will change position with the switch. I can manually turn the selector on the transfer case with pliars and with it running in neutral I can hear it clunk into gear while I do manually select. I am at a loss now...

 

[adsm08]

When you shift the case manually into a 4x4 selection, what happens if you try to rotate the front drive shaft by hand?

 

[RonD]

When you turn on the key the 4WD lights should flash on then off as a Bulb Test, as should other dash lights, its not a 4WD system test.

The 4x4 module controls the shift motor and the dash lights
But the dash lights only come on when shift motor is in the correct position for that light, 4high or 4low, thats via contacts in the shift motor housing

So when shift motor was off the transfer case and you change to 4high, as an example, did the 4high light come on after shift motor moved?

The clicking from 4x4 module is the 12volt relays closing to send 12v and Ground to shift motor to move it counter clockwise, or Ground and 12v to move it clockwise, just like power window motor works, up/down
Both relays are grounded when "open", so only one has to close, apply 12v, to establish direction of motor.

After your testing, as adsm08 says, problem may be in transfer case if manual shifting did not change state of transfer case.
Block one wheel when doing this as the transfer case DOES have a Neutral, it isn't marked, but is across from 2wd, between 4h and 4l