Recent replaced my tcase with another used tcase....4x4 worked while on the lift and once I pulled it out of the shop and turned it around I put it back in 2wd....didn't get 1 block up the road service 4x4 light came on and now 4x4 doesn't work....lights on the switch light up when vehicle is started but go away after and selector switch doesn't work.....all this worked b4 I replaced the tcase(clutch was bad in old tcase).......I've checked the fuses I could find and came up with nothing....bad switch? Tccm? It'd just weird that it all worked b4 and after tcase was replaced but now I have nothing.....have checked connections and wires going to the tcase

 

You likely have a bum t-case or wiring not matching up. Could be a bad connector. Can you get the old connector back?

 

The 4x4 worked worked once I got it on the lift...tcase is good....we checked connectors

 

Did you replace the exact model? How about the year? I'd fire some contact cleaner in the actuator and wiring harness plug,let it dry for a few minutes, then put dialectical grease to seal it up.