No crank/ no OBD power/ no gear indicator illumination
 

Hello, first post here, looking for help, any is greatly appreciated. The truck is a 2012 Ram 2500 6.7 diesel 4x4 226,000 miles, auto trans. No crank with key turned over, no obd power, and no gear indicator lights on dash. All other dash lights illuminate. Windows do not respond to buttons, and no radio power. HVAC functions are working. Shifter locked.Charged batteries to make sure they were not an issue testing good with load tester. Checked under fuse box for chews or bad connections, none found. J3 PCM fuse is ok and not blown.Not able to read codes, I jumped to the conclusion to check ECM first (on block) which may be wrong but it's out to be tested and will be back in the next week, it is a free test at the rebuilder. Has anyone ever heard of these issues or have any suggestions? I did jump the starter relay and it will turn over but will not start.

How old are the batteries? 5 yrs or older replace them both. They do weird things when they die.

one is new and the other is charged fully, but just to be sure I'll put a new one it its place today and report back. Thank you.

Never replace just one unless you enjoy replacing one now then two again in sometimes a few months. An old battery will kill a new battery,