car goes in for a stern fixing tomorrow[1]. I got it running yesterday after a lovely charge went into the battery, got home today and the car is under 2 inches of snow... probably not the best environment to ask a worn out car with an ill charging system to start in, it turned over nicely, but only fired once in a blue moon. So, I took the HT leads of and blew wd40 in the ends, at the engine end I've neglected the middle two cylinders because I can't get the HT leads off in the dark. Anyway, that was good enough to make the fires start. The battery is now off the car and back on charge because I did crank it over a bunch of times and I really need to get it to the garage tomorrow. [1]Crux of the issue: foot on go pedal, vroom. foot off go pedal, a spark from somewhere down near the alternator. at idle, 14V across the battery, no wobbling. What makes alternators dump excess charge to ground the wrong way?