Okay so I bought my truck and the guy told me the 4x4 didn't work so I started to see why!!!!!the truck has a electric switch when I would turn it on the truck wouldn't engage no sounds that it would engage. So I started with the fuses all good check the vaccum lines all good so I turn my attention something electrical I changed out the Transfer Case Motor and added some new Mobil 1 oil and it worked if ppl are having the same issue check the transfer case motor

 

Yep...sometimes the T-case motor just needs a tap with a hammer to free it up...nice job !!