Bucks, do you have a battery charger? If the alternator is good, charge the battery and see if it keeps it's charge. Sounds like , if it isn't the alternator(which is the most likely suspect, given the spark) that maybe you have a drain in your system related to the electric fan hookup, or any other new wiring. If you take the battery to Autozone with the alternator, you can kill two birds, with one stone, so to speak!