Great idea for that empty space.
You should recheck that one crimped wire on the fuse block and the other one with the bare wire.

 

Nope. The red wire on the right not connected to anything.
Sorry... I've got OCD when it comes to electrical wiring. I blame my old aircraft maintenance days. lol

 

The bare wire runs to the distribution block on the battery that is out of the truck now.
The crimped wires all have heat shrink on them now, these are pics from back when I was doing the install.
I was just trying to suggest an alternate location to wire in something, I wasn't trying to suggest how one should go about wiring. I personally have confidence in the safety of my setup.

 

Thanks fellas. At first I was looking for a little more direction regarding that styrofoam, but after you shared your solution, R0VERGUY, I found that it was a brilliant idea! Close to the battery, protected, clean, dry, easy to mount to. Perfect! I just relocated my jack back to one of the side bins in the back, since I don't have 7 seats, and the rest of the jack bits are back there anyway.

Thanks again!

 

I hope it works out for you too.
I have a 6 slot mini fuse block in there right now and I still have room for 2 more add-ons in the future.
I have my main power cable running the short distance from my battery to the mini fuse block, then the fuse box splits power to 4 relays, my main switch panel inside controls each relay, and the relays run power to my accessories when told to do so. I've never had an issue with my setup, but I'm not a master electrician and can't guarantee it's up to code

Here is how is sits now. (One of those 3 switches controls my rear spot lights and it great for people behind you who forget their highbeams are on, you can probably guess which switch controls which lights one by the lables)