I have the drive train, computer & wiring from a 96 Dakota in my old Dodge truck.
What is your "old Dodge truck? You may want to drop the pan and look for any obvious issues. You can always run a pressure test to see what is what. If you have the "check engine light" hooked up you can do the key dance to get codes.
https://www.allpar.com/threads/the-1980s-1990s-chrysler-computer-codes.229009/#post-1085223107Pressure test is on the last page...
https://www.trucktransdiag.com/downloads/technical-data-for-dodge-transmissions.pdf
