A deep dive into Fusible Link Wires

From RVelectricity subscriber Bill Morgan

Hey Mike,

A little more info on Fusible Link wires, if I may. The purpose of a Fusible Link is to introduce a calibrated weak point in the wire run which like a fuse will burn out before compromising the full wire, and the short length will not produce voltage drop.

Fusible Links are more dependable than cartridge fuses since they are not affected by heat, moisture, dirt, mud, grease, etc. and can last as long as the original wire harness. Fusible Links should not be used in the interior of a vehicle, because a burning Fusible Link will produce sparks and smoke. Fusible Links have been used in OEM wiring on many vehicles for over fifty years and are extremely dependable as well as being inexpensive.

A Fusible Link wire is generally four wire gauge numbers smaller than the wire being protected, eg. 18 AWG (American Wire Gauge) Fusible Link for a 14 AWG wire, 16 AWG for a 12 AWG wire, 14 AWG for a 10 AWG wire, 12 AWG for an 8 AWG wire.

The gauge may be printed on the wire or on the connector, and may also be indicated by metric size, eg. 0.8 SQ mm = 18 AWG, 1.0 SQ mm = 16 AWG, 2.0 SQ mm = 14 AWG, 3.0 SQ mm = 12 AWG.

They are usually about six inches long +/- ½ inch and have a crimped and soldered ring connector on one end with an insulated connector on the other end to connect to the larger wire.

Fusible Link wire can be purchased at most auto parts stores. - Bill Morgan

Thanks Bill,

Great write up on fusible link wire.

Everyone: Remember that if you do find a melted fusible link you need to replace it with the same gauge and length of fusible link wire. It’s there for a reason, which is to protect the rest of your wiring from meltdown.

Let’s play safe out there… Mike