Fuseable Link.

[Windowsrookie]

I upgraded the positive wire from my alternator to 4 Gauge, the old wire had a fusible link on it. What is the purpose of the fusible link, and is it still needed with the 4 gauge wire I upgraded to? I also plan on installing a higher output alternator in the future, does that affect anything?

[Eagle]

The fusible link is a fuse. The purpose is to protect the system, and to reduce the possibility of underhood fires. If you replaced the fusible link with a heavier gauge wire, you need a fuse. You can get heavy-duty, 100-amp in-line fuses at marine supply places, and my brother told me that Auto Zone may now carry them.

[Tomahawked]

A fusible link is designed to break if the maximum rated load of a given wire size is exceeded. So if the 4 ga wire is rated for more than what alternater produces, just fuse for it instead.