Confusing Ground Fault

[L. Daily]

Hello everyone.

I am new to this forum and I joined because I have a very specific problem I am trying to figure out and have been unsuccessful so far. I have a 1983 Dodge Ram 3/4 ton 318 pickup having a starting problem. I was doing this number- turn the key and then Woo---Woo---Woo---and then WOO Woo Woo and starts. Then nothing. I turned the headlights on and nothing. I knew battery was low and cleaned the terminals and jump it. i inspected the battery and justiled the wiring a little and headlights came on. Went back in truck and it started. Used truck and then shut down. When I came back to start it again- same problem. I suspected a short in the wiring somewhere. When I got out again I went back to the negative terminal again and shook the wiring coming off of the negative post- and noticed it was red hot. Smoking. Well, I thought I had found the problem. I disconnected the battery ground and removed. I went to the parts store and purchased a new negative ground wire. It was attached from the battery to the side of the radiator. I also bought a new negative battery terminal and cleaned up both battery terminals before attempting to start again. But when I re-connected the terminals the new ground strap I had just put on began to get very hot immediately. The ignition switch in the truck was in the off position! I quickly pulled the ground terminal off the battery and noticed the ground post had been deformed somewhat from the electrical arc! Well in my limited knowledge knowing the battery was older I suspected that maybe I had a defective battery, maybe internally shorted out or something? I went back to parts store and bought a brand new battery. Installed it and reconnected the posts, and again the brand new ground strap began getting very hot and smoking. Surely a short or stuck connection somewhere- but at this point I do not know what to check next-ground to solenoid? Solenoid to starter-Battery to body, Battery to engine? Voltage relay, or voltage regulator? I do not understand how a ground strap would heat up just by connecting the terminals with the ignition switch in the off position??? Can anyone out there enlighten me as to what could cause this? And yes the battery is connecter + and - correctly. Could it be the ignition switch itself? Thanks for any feedback. L. Daily