Fusible Link
 

My car is slowly going dead as I drive it. The guage reads a very slight drain, but if I turn the lights on, it goes was over towards drain. I just had the alternator checked, its fine. The guy at Autozone said maybe I've got a fusible link that's done its thing (fused). My question is, is the fusible link the rubber thing that's in line to plug into what looks like a condensor on the back of the alternator. If not, where is it? Also, what does it protect? I've also just replaced the voltage regulator, and I'll probably replace some wiring that seems like its past its prime this weekend.
Thanks