duster under dash wiring help

Back to the original problem before you smoked wires.
Check the amp gauge.
Check the ballast resistor, when they take a crap they act the same way, spark when cranking, dies when you let the key off.

If you connot get it running check the following:
Control box, coil, and pickup in the dizzy,

Also check the voltage in the battery and output of the alternator when you get it running.
Over charging alternator will complety fry a Mopar wiring harness.