Instant loss of charging... car is now dead on road...

Ok my guess is your alternator has a sperratic dead short in it. I had one like that and the symptoms were the same. The inside of the alternator is all jacked up is my guess. It had a high end miss too before it took a **** on me. Couldn't find out the problem got it running, revved it up and all kind of sparks and **** were coming from inside the alternator at about 4 k missing like a sumbitch. Replaced the alternator, walaaa all good.