The alternator could be throwing out too much voltage. Have the alternator and regulator tested. If you could get hold of a voltmeter, turn the car on (if you can get it to idle) and put the positive lead from the voltmeter to the positive battery post and negative to negative. If it reads 12.5 to high 13's its fine. If it reads 14's or more, the alternator is throwing out too much voltage (bad regulator), which can blow the fuse.