Highly unlikely to borderline impossible that you caused any damage. In fact the only way you could have hurt anything is if you ran a new sense wire to the battery or something.... then the alternator might have to run at 16 volts to push enough through the tiny stock wire to make the sense wire happy voltage wise. That shouldn't even tickle the alternator though. Unless you melted the stock alternator wire you probably have a bad alternator if it isn't working anymore. Things that kill alternators are Heat and miles. If it was a self sensing alternator then there is zero chance you hurt the alternator and a slight chance you could melt the stock wire.
