Mopar dies when key is released

OK< as I told you earlier, I'm not specifically familiar with "the later stuff"

The only difference is that the later relay added a second contact, and the pin marked "ballast resistor" now became the ballast resistor bypass circuit. That terminal goes essentially directly to the coil + and supplies starting voltage to the ignition circuit.

I'm certain that your problem is between the ignition switch --harness connector -- bulkhead connector--and the "run" buss out in the engine bay.

Without a GOOD wiring diagram I cannot give you more specifics.

You should be able to ID where that wire comes through the bulkhead, probe that, and determine if you have power there. If (seems to be) there is a fuse link, that would be suspect