Maybe someone can help the electrically challenged such as myself.... I need to add another fuse block but don't understand why some have a negative bus and some don't......I surmised the difference but why would they be... always thought fuse blocks for autos had both + and - terminals
Blue Sea Systems ST Blade Fuse Block - 12 Circuits with Negative Bus & Cover New
Blue Sea 5028 ST Blade Fuse Block w/ Cover - 6 Circuit without Negative Bus