Quote Originally Posted by jerry clayton
If you have the relay hooked to the negative terminal you have the polarity backwards---is the batt hooked up reverse?? if not you are probably creating a direct high amp short anytime the relay is energised!!!!

If you have a voltage regulator you have probably damaged it , if your alt has internal, you probaly damaged it---or both!!!
Don't have relay just grounded the fan to the cable, no voltage regulator and the battery isn't reversed