OKAY HERE GOES I hope you can follow my train of thought:
- You have 5 wires, 16-ga going to the battery individually
- Looks like each wire is no longer than 4-feet in length from battery to your fuse/relay box
- One 16-ga wire is rated for 15 amps max (at 2 to 4-feet)
- Multiply by 5, the math says 75 amps max if everything is turned on
- One 10-ga wire is rated for 70-amps max (at 2 to 4-feet) - not enough, BUT...
- ...One 8-ga wire is rated for 120-amps max (at 2 to 4-feet) - more than enough.
I would cut out one of the open areas in the fuse/relay box (the center portion of the box that gets sandwiched between the bottom and the cover pieces) and mount a junction block to it, something like this:
Link to item on Amazon.com:
http://a.co/1NvQfXQ
Next I'd solder up a single "main cable" out of 8-ga wire with ring terminals at both ends. This main cable will run from the junction block, out the bottom of the fuse/relay box, to the battery (+) terminal.
From here, I'd use shorter 16-ga wires with a ring terminal at one end to connect each relay's 12v terminal to the junction block.
This would make everything cleaner, with one single wire to the battery terminal. On top of that, if you ever want to use the extra fuse spots in your fuse/relay box for other lower current accessories, you just have to run 12v to the junction block (which is already in the fuse/relay box), and the 8-ga main cable will still have enough reserve capacity to handle any extra amp draw. You won't have a spaghetti of wires (and a bunch of ring terminals) running to the battery terminal.
::smile::