Done alot of searching on this topic but still at an inpass.
I'm getting no power at the transfer case while shifting to 4x4. I have lights on the cluster when I turn the ignition on but nothing after that.

Things I have tried are:
Checked and metered all fuses related to a esof problem. Swapped both esof relays beside the drivers battery(tested working in my other 03 truck), also removed/tore down to check wires condition. I've probed the plug from the switch on the dash and have 12v at the dark blue wire only(unsure if this is normal).
I've also obtained a gem 4x4 module from a truck I watched the 4x4 engage without fail.

Still no power to the tcase. Only thing I've not tried is a new switch..... or possibly start tracing the wiring for a broken wire. But with power at the switch why isn't something happening?

 

Could be a bad switching motor or as you mentioned.... the wire.

Could be a grounding issue as well.