The primary function of a fuse is to protect electrical systems from short circuits and other types of faults that can lead to fires or damage. In the case of an amp wiring kit, it acts as a fail-safe device by interrupting power flow when too much current passes through it due either accidental grounding or ground shorting where positive wires touch bare metal parts which would cause excessive heat build-up eventually leading up-to melting insulation thus creating intermittent connections causing garbled sound output. Fuses are normally inserted at points within circuits closest to power source terminations so they should always be installed near battery positive post before running any additional wiring along vehicle chassis!