73 Duster crank but no start / blowing in-line fuse on red ignition wire

Hello, all!

I’m new to the forum, and per everyone’s guidance, I’ll post my issue here. I just bought a 1973 Duster last Monday, started driving it home for about half an hour on the highway, then it backfired and died, and wouldn’t crank/start. I had it towed home. After opening the hood, I noticed that the ignition module was cooked, and the potting ran down the inner fender.

I was able to trace the cranking issue back to under the dash where someone added an in-line, 30a fuse on the red ignition wire. After replacing the fuse, the car will crank, but if I leave the key in the “on” position, it will blow the fuse after a second or two.

My gut feeling, and my brother-in-law ‘s (mechanic, coming over shortly to help me track this issue down) opinion is that something’s drawing hard on this wire, and/or there’s a short somewhere.

I pulled the ballast resistor, and it is cracked up, so I just replaced that.

Any guidance on where to look next is much appreciated! We are checking out the bulkhead connection at the moment.