Not sure what more I can add here other than it appears to be a poor connection for sure. Arcing the battery posts is a pretty strong upset to the system but I can't quite explain why it results in a successful start.


When it comes down to it there is a pretty low parts count in the starting system so just good old parts substitution should reveal the cause.

Also, here's a tip from years of experience. Don't always assume a new part is good. I have chased many electrical problems that turned out to be extremely difficult to find since I assumed a new part must NOT be the cause.

Have you tried a different battery of known good condition? I've had one with poor plate connections between the cells that would come and go with vibration and load. That battery blew up nicely one day while heavy load testing it. That was fun to clean up and luckily I was turned away from it when it blew so only my clothes were ruined.

Sorry I can't help more but it's tough to diagnose over the net.