4x4 Doesnt Work after 2.9 to 4.0 Swap

[Hitchner2009]

Hey guys so my 4x4 doesnt work after i swapped in the 4.0 from a 2.9. I have a 1987 Ford Ranger 4x4 with supercab, the engine harness and computer came from a 1992 Ford Ranger 4x4 4.0 supercab. I was told that the Transfer Case is on a system of its own and should have stayed working, well when i went to test the 4x4 i have no power to the switch and the truck doesnt engage into 4x4. I know for a fact my 4x4 is capable of functioning as i used it just before the engine conversion. Any help would be greatly appreciated, im wondering if there are wires that need to be spliced or something from the 4.0 engine harness into the 2.9 dash. Anybody who can help me get in the right direction?