Wire is measured in "gauge" often abbreviated AWG for "American Wire Gauge" The lower the number, the bigger the wire. Bigger wires handle more current (amp) draw. Check out this cable calculator chart to learn more .

Again, a fusible link’s function is very similar to a fuse. It’s designed to fail before your wiring harness melts to goo.

As a general rule, a fusible link is made of wire that is four gauges higher (smaller) than the rest of the circuit, making it the weakest link in your electrical chain. For example, a fusible link in a 10-gauge wire would be 14-gauge.

The smaller-gauge wire handles less current than the rest of the circuit, so it will overheat first and, by doing so, will break the physical connection between the wire to which it’s inserted.

Replacing a Fusible Link

Replacing a link is as straightforward as cutting out the broken link and installing a new one.

Many fusible links now come with a crimp connector pre-installed, which simplifies the installation process.

Remember to weather-proof your connections—cover your joints with heat shrink tubing or tightly wrap your connections with electrical tape.