I think you have already cleaned any corrosion from battery terminals (vingar will work).
While the motor was last running you heard something pop 4 times?
Sounds maybe like a pinched or loose wire.
At this point I would be looking around for a short to ground o rblown fuse.
Beyond that, will have to go through and find where the 12V "ain't".
Need to know what is working.
1st check the lights and blinkers that will work and include the running and brake light.
"started it up all i got was 4 electrical pops and it abruptly died."
sunny wrote on 12/31/69 at 16:00:04:horn blows. lights come on.