Hyundai Repair: my alternator keeps frying, alternator belt, golf cart

Question
my husbands brother jumped this gas powered golf cart of my car then that night the battery light went on and soon it died so i got a used alternator and new battery its been fine for two day i just turned the lights on again and the battery light went on and the car eventually died could it just be another bad alternator or could it be something else that is burning it up from him putting the cables on both of the terminals could it be the ECU?  

Answer
Used parts are always suspect.  If your alternator belt is properly tensioned, you should replace the alternator again.  

If you've got a four cylinder, I suppose there's a remote possibility the ECM could be the issue.  It wouldn't make much sense, though.  You say the alternator worked okay when first installed, and then stopped working.  If the ECM had been damaged by the jump start, I would expect the alternator lamp to have been on immediately after replacing the alternator.

If you've got a V6, the problem cannot possibly be the ECM because the alternator is not controlled by the ECM.