skinny

Ok so last winter I had issues with the B+ wire (normally 10g) comming apart right at the alt first was a crimped one. So I ran heavier wire figuring part of issue might be the draw on it this was ground cable from a welder so plenty big enough
the end is a copper solder on end and it has lasted all summer but now winter is back I just had to do the repair

could there be something drawing hard enough to cause enough heat to melt solder

I know last year I had bad heater fan switch but I swapped it out in summer with a second good at the time used

so I'm looking for ideas and or answers to this issue