So my car is up at PMB performance for a little work. I am not much of an electrical type person, when it comes to cars. So I asked them to install fuses and relays for the headlights, fogs and horns. You know, switches getting a little old and don't want to put undo stress on them.
This is a picture of where they installed them. I think they did a nice job.
The fuse box is a BLUE SEA SYSTEMS–ST Blade Compact 4-Circuit Fuse Block
The relay box is a HELLA H84988001 4-Way Mini Relay Box Kit

Greg W.

I did a similar thing with the 4 un-fuzed positive wires at the battery.
I'd installed a new to me wiring harness and wanted to make sure everything was hooked up properly. i'd hate to have some burned up wires after all that work.

Click to view attachment

IMHO & if you have a choice, fuses are best placed before all the wiring that provides the power. The basic fuse panel under the dash or close to the battery is actually the safest way to go. Fuses at the battery are the best.

That firewall setup is slick.

Unless I am mistaken, the fuses do come in before providing power. The hot lead is at the bottom of the fuse box, through fuses with, leads providing power to the relays. The switches at the dash are just switching the relays on and off.

Greg W.

There's a set of wires that are un-fused for a considerable distance, one set goes to the engine bay relay board, one going to the under-dash fuse panel to fuses 10, 11 and 12, and one going to the ignition switch. So if any of those wires chafe and short to ground, there's no protection of any kind.

Understood, I thought you were talking about the picture in the original post.

Greg W.

What size wire did you use from the Battery to the Fuse box, what size of fuse and I assume the four wires from the fuse box are 10/12 gauge wire?

Not sure of the wire gage, but it measures .285" over the insulation.
It's some leftover I had from a marine project.