100 amp fuse keeps blowing

I'm having a problem with my 99 nissan altima's alternator and battery system after I accidentally touched (with a wrench) the power terminal of the alternator while the battery was connected causing a spark. Something keeps blowing the 100amp fuse that is apart of the cable system connecting the alternator with the battery. It blows when I attach the positive end of the battery cable. I think a short to ground would cause the fuse to blow and the only major things in this system that is capable of blowing a 100amp fuse are the cables, alternator, 100amp fuse and the battery. I disconnected everything and I am not getting a short to ground in the cables. With the alternator removed from the car, the positive power terminal on the alternator has continuity to its case (ground). The same happens if it is connected in the car except it also has continuity to car ground. I took the alternator into Auto Zone and their tester checked it out fine. If the alternator is fine and the cables are not shorted to ground what could possibly causing that fuse to blow?

The car will still start up and run but a lot of things aren't working including windows, a/c, blinkers, all of the dash lights gauges. The things that do work include the lights, emergency flashers and radio.