My light does not come on when I switch to 4x4 and the truck does not go into 4x4 when I manually lock them from the hub

 

Check your vacuum lines going to your hubs.

 

Possible solenoid out for transfer case... I have read about it but dont have it down enough to give you proper direction. Hopefully someone with more exp will chime in soon.
also check fuses JIC
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Engage both front hubs and get under the truck and see if you can turn the drive shaft between the transfer case and the front axle. If you can you have a hub not engaging. If you can't there is something going on either with the shift motor on the transfer case or something mechanical inside the transfer case.