A fusible link is a short piece of wire that is covered by an insulated cover. It is several gage sizes smaller than the circuit it protects. It will melt in an overload situation, opening the circuit.

The starter and other circuits have fusible links. The size is printed on the insulation. If the insulation is burned beyond recognition, consult your Isuzu dealer/retailer for the proper size. Replace a fusible link with one of the same size and insulation type. Fusible link insulation is a special purpose high-temperature material.