Aux fuse box (1 Viewer)

[Ghostrider I]

91 HDJ-80, with a 140 ah alternator. I have two auxiliary fuse boxes one in the right side kick panel, the other on the left side firewall in the engine bay. Both are wired to the left (when in the truck) battery.

My question is, can I add a third?

 

[Feistl]

You can have virtually unlimited fuse panels and accessories connected, it just comes down to making sure your average constant load is less than the output of the alternator. Remember alternators don’t always put out their peak, and not all devices pull current at their rated load.
If you are running a lot of devices I would temporarily put a shunt inline so you can actually measure how much you are drawing...

And as always, make sure the wiring is up to the task and that it’s fused with a fuse capacity LOWER than the rating of the wiring. In the past I have grabbed mini distribution panels which I mount right next to the battery...

so it goes battery terminal to distribution fuse panel with 0 gauge wiring (I also personally run fused battery terminals). The distribution panel then has ~8 very large fuses (60-120amp) which then run to other fuse panels (the gauge of wiring is usually 2 gauge).

wiring up a vehicle isn’t difficult, just spend the money on quality wiring, get decent OEM fuel panels from late model vehicles from a wrecker and ideally spend the timing drawing up wiring diagrams (I use a program called tinycad, but I’m sure there are better programs out now).

finally, if you are running a lot of stuff I recommend getting a doner wiring loom from a late model NON-Canbus high spec car (~2000-2010 Range rover) is a good choice as it comes with a lot of long wires. That way the wire is relatively new, contains lots of unique colours which are very long. Combine this with a well draw wiring diagram you print, laminate and keep in the glove box and you shouldn’t have any issues.

cheers

 

[Ghostrider I]

What, exactly do you mean by having the wiring with a fuse lower than capacity?
These aux boxes have positive terminals which I clip in (forgot the name of the connector), pop a fuse in usually 20A, and run a ground.

 

[Feistl]

So say you put a 3rd fuse panel in the rear of the car... you anticipate you’ll use a maximum of 50amp at any given time.
You should install a 60amp fuse as close to the battery terminal as possible, then run a 80 amp capacity wire from the fuse to the rear fuse panel.
What you want to avoid is using a 60 amp fuse then running wiring only rated to say 50 amp.
The fuse ALWAYS needs to be rated lower than the wiring running to/from it.