1972 Chevy Blazer Ignition Switch Smoking

[ABCEDERWALL]

double checking all of my electrical... does anyone know why the inline fuses that are on the wires 1 & 12 running from the dash cluster connector to the battery (black w/white wire and the black wire) require 4 amp SHORT fuses?? I found the one on the black w/white wire, but I cant find the one on the black wire? I'm assuming I need to add one? Currently my stock ammeter gauge doesn't work, and this is the only thing that I see missing?? Any input would be appreciated??!! I have a gauge cluster, not dummy light set up...