Ellicott City, MD
We can understand, using an extreme example.... Let's say someone took the thick positive wire off of the Alternator entirely.. Charging goes away, and we're down to just the voltage in the battery. --Things would get slightly dimmer, but wouldn't go out entirely...
I guess now I vote for an intermittent ground (and it would have to be really close to the battery, in order for everything to go crazy like it did... With the weekend coming up, I'll have the light & time & energy to try to trace the batt neg cable.