Help Firing Dad's Dart up Again - SOS - No Spark After Hosing Off the Dust

Everyone, we've got a running car again. I got on the horn with Ryan and we went over all of the advice we received, talked it through. Parts were bench testing fine. We just couldn't put on finger on it. We finally just made a temporary ignition harness and bypass the main harness and it fired right back up. So Dad definitely has an engine harness issue going on, so I'll look for a new engine harness to put in it. Somewhere there is short that had just enough corrosion on it to work fine until they washed it and then whatever issues Dad was having 30 years ago bit us hard.

6 or so wires later connecting the distributor, coil, ballast, and ICM and we're back in business. It's good enough to drive the 1/4 mile down the street and back and I'll just plan on putting a harness in it on March when I have a week off to work on it more.

Really, I can't say enough thanks to all of you for the posts, it saved me from searching for it all while trying to hide from my parents without them getting annoyed (my mom was definitely getting peeved I was either in my phone or at my computer far too often today). So we're in the clear! Car goes back to Dad's tomorrow, and we reveal with the patched together harness on Thursday, and come spring we'll fix it up and he'll be back in business. I'll update again after we let Dad see it!
Chrysler factory info about the 1974 Seat belt Interlock system here:
MyMopar - Mopar Forums & Information - Browse MTSC by Model Year - 1974

The schematic below will give you starting point for troubleshooting the start. When the key is turned to start, only the Ignition 2 and Starter relay wires are connected within the switch.
As you know by now, 73 and 74 are not the same - especially with respect to the buzzer and interlock. So exactly how that, including the overide, ties in will be the puzzle for you to solve.

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