Ermocida

Need help. I have a 2004 Chevy avalanche . I changed the transfer case. With a used transfer case off of a . 2000 Chevy Tahoe. I installed transfer case and found that the connector is different for the wire harnes. So I tryed splicing the wires on to the Tahoe harnes . It did not work. I have no lights on my 4 wheel dr panel. And computer reads service 4 wheel. Does any one have any advise

tech2

were the build codes on the tcases the same?
if yes, splice the old connector back to the vehicle harness and swap the tcase encoder motor from the original tcase to the replacement