Just because your cables were hooked wrong,doesn't mean that you blew the alternator out. Does it have voltage going to it ? Does this have a main fuse on it.Usually the main fuse to the car will blow before it goes anywhere else.If you think the alternator is not charging,what you can do is when you turn it off,run a draw test to it and see if you might have a draw.if you suspect the alternator,first disconnect the regulator see if the draw goes away,second disconnect the main wire, to see if you may have bleown the diode plate off. "this is done by hooking up an ammeter in-line with the negative cable on one lead and the other lead on the battery. If you don't have an ammeter,try a test light lead on the cable ,light on the battery. If it's really lite up would indicate a big draw,such as 1-plus amp,dim,opposite.
Not as confusing as it sounds.