First Time Start....Melted Wire....Help

No Quick Aw-Haw...unfortunately..There is obviously a problem with the accessory feed to the starter solenoid somewhere. I disconnected all of the interior fuses in order to isolate the short. There are only a few wires going into the solenoid..... Accessory feed from the battery, jumper from the accessory feed post to the bulkhead connector (to provide power for interior), the violet wire that feeds the horn relay. There is the feed to the neutral safety switch and the yellow wire going to the bulkhead connector which I think is the solenoid trigger from the ignition. I got out my test light, rigged up a 30amp fuse in line from the battery and started poking around. Only my accessory power is hooked up, not the main power lead to the starter. Here are my observations: When I hook the test light ground to the battery, I have power at both the main feed post AND the single wire leading to the starter solenoid. When I touch the test light to the yellow wire, I hear the solenoid "click". My thought is that there shouldn't be power at the starter solenoid feed until the key is turned on and "bridges" power to the starter. The minute I connect the battery's negative post to the vehicle ground...POP, goes the fuse! The problem with the electrical diagrams I have is that the 1965 version doesn't have electronic ignition. I also have a diagram from a 72' Plymouth that uses electronic ignition. I have been able to plow through this restoration with the help of my FABO friends so far. Please give me some insight. Thanks