It's there to minimize static when using an AM radio. It's supposed to be connected to the Armature terminal, but if it gets left off, you're not likely to notice any difference in charging system performance. Definitely don't connect it to the field terminal.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!