Why not wire it correctly? There's no reason not to use the ammeter in the circuit- - - -it doesn't care what's providing the charge current- - - -a generator, an alternator, or even a couple of hamsters running in a cage!
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!