[NoVa-Corvairs] Problem with a friend's car

[Daniel Goldberg]

A friend of mine is having the following problem with
his old car (BMW, not Corvair):

"I'm also in the process of checking/replacing all the
various ground wires on the car, since it appears that
my electrical issue is most definitely ground-related..
 Most recent symptom is that it will
idle for hours with all accessories on and not lose
charge, but once it's moving it loses charge...  I
*love* a good mystery."

Any ideas as to why it quickly loses charge when he
puts it in gear?