If you connected the cables in the positive ground position, you've definitely fried the alternator rectifier if you left it connected for more than a few seconds. There's no circuit protection to prevent a dead short through the alternator with the polarity reversed.
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!