LOL....ya 17 volts is a tad bit high. all kinds of strange things can happen when an alternator starts to fail. its not a harness or anything. if somthing had shorted there would be either a fire of no charge whatsoever. a higher-than-normal voltage is really strange, and my guess is that the voltage regulator is fried. more than likly you have guessed correctly, its time for a new one. do a search for alternator replacment writeups, theres a good one here somwhere.