New here,
Just put the 6.0 back in the truck, engine working good now. Went to take it for a test drive and the transmission will not engage in any gear. I don't have any codes coming up on my scanner. Can not figure out why the transmission is not working from engine R&R.

Fluid level is good
Swapped wiring harness from my other truck and still nothing

 

No codes at all? Not even P1000?

 

None. I probably need a better scan tool
any other ideas would be much appreciated
torque converter bolted in original position. Never came accross this problem before

 

If there are no codes at all then there is something wrong with the computer or scan tool. After an engine change (the batteries were disconnected, right?) there is a P1000 code set. If you can't read this code you need to fix that first so you can read error codes.

My SWAG is that you're missing a power or ground connection that is affecting the computer.