So I'm driving my '89 the other day (auto tranny) on the highway.
Everything's fine.  All of a sudden, I lose all power.  Fortunately, I was
going fast enough to coast in fast traffic two lanes over to the right, get
to an exit, coast on a downhill ramp, time a traffic light with the brakes,
cross the intersection and into a parking lot, where I was barely able to
make it over the driveway lip.  (Somebody was smiling on me, for sure).

Anyway, my battery's dead.  I wonder why my alternator idiot light never went
on to warn me of a problem.  I got a tow. Later back in my driveway, with
just a little reserve power left, I was actually able to start the engine and
run for a minute.  I noticed though that when I was in park or neutral, the
light went on.  In drive, when you really need such a warning, it was off.

Okay people, does anyone know of this peculiar behavior, or are my wire's
crossed??

Thanks.
Sam