I had to jump start my plane (using the Piper External Power port) (yes, I
stupidly ran down the juice when I thought a gas smell was coming from a
flooded engine when it wasn't). I turned on just the battery half of the
master while I did it, and the plane started ok.

There was an annoying whine in the intercomm, and it took me a good amount
of time (15-20 minutes flight time) to realize that the alternator guage
was pegged, and cycling the alterator half of the master switch off and on
again got the alterator guage down from being pegged, and got rid of the
whine. I suspect that I misread the sign language from the guy who was
helping with the jump start, and I turned on the alterator before he
unplugged the external power.

Does this damage the alternator in any way?

--
Paul Tomblin http://xcski.com/blogs/pt/
Endless Loop: n., see Loop, Endless.
Loop, Endless: n., see Endless Loop.
-- Random Shack Data Processing Dictionary