Blue Sea fuse box questions

Hello All,

I'm planning on adding some more lights/aux stuff so I'm looking at making a aux fuse box. I've read a lot of different threads on here and just want to make sure I have everything correct before I buy stuff.

Buylist:

$40 Blue Sea Systems 5026 ST Blade Fuse Block 12 Circuit with Ground and Cover

Blue sea fuse box

$26 4 Gauge 4 AWG 5 Feet Black + 5 Feet Red Welding Battery Pure Copper Flexible Cable Wire - Car, Inverter, RV, Solar

4 gauge

$25 T Tocas 100 Amp Circuit Breaker with Manual Reset for Car Audio Solar System RV Truck, 12V- 48VDC, Waterproof (100A)

100 amp breaker

$26 irhapsody 5 Pack 40/30 AMP 12V DC Waterproof Relay and Harness - Heavy Duty 12 AWG Tinned Copper Wires, 5-PIN SPDT Automotive Relay

Relays

Things I'm a little confused on still:
Why do some builds use relays but others don't show any?
What I'm missing?
Best mounting solution?

Thanks in advance for the help.

 

Relays are just remote operated switches. Allows you to switch on/off something with a high current draw from a smaller wire/switch.
For example, installing a light bar that needs a bunch of power and it’s 2’ from the battery, you could run a bunch of wire into the cab to a switch and back to the bar, and it would need to be sized appropriately for the power draw and length. Or use a relay and run a ‘signal’ small wire to the switch inside.
I’m sure there’s some good websites that cover basic wire size selection and fuses, etc you should read up on before doing this.

 

You can use a smaller gauge wire from your lower amp cab mounted switch to the relay. 8 or 10 gauge would be sufficient.

 

I'm looking to do a similar project.

I'm going with the Blue Sea 12 circuit box and Blue Sea 187 Series Circuit Breaker 100 amp and 4 gauge wire.

I'm having a hard time finding a good mounting plate for under the hood though (2008 2nd Gen). Found a Pelfrybuilt one, but obviously they went out of business.

I'm interested in what you find out! Thanks!

 

These guys make a holder for your application:
https://www.paranoidfabrications.com/collections/toyota-tacoma

 

Thank you. And at a reasonable price!

 

Check out Powertrays.com. He is also a vendor on here. He sells a nice aluminum tray for all of the components and sells a complete kit with the Blueseas panel, all wiring pre-cut/crimped, etc.

 

How many switches will you be running?

12V Auto Waterproof Fuse Relay Box Block [6 Bosch Style Relay Holder] [6 ATC/ATO Fuse Holder] Universal Relay Block Box for 12V Automotive Vehicles Cars Marine Boat Jeep Light Equipment

$22 True Mods 12V DC Auto Waterproof Fuse 5-Pin Relay Box Block [6 Bosch Style Relay Holder] [6 ATC/ATO Fusible Holder] Universal Relay Block Box for Automotive Vehicles Cars Marine Boat Light Equipment

https://www.amazon.com/dp/B07MR64XK1/ref=cm_sw_r_other_apa_i_HUuyEbKAEDC57

 

I personally like the Bussmann box better.

$62 COOPER BUSSMANN - 15303-4-0-4 - FUSE RELAY BLOCK, MINI, REAR TERMINAL

https://www.amazon.com/COOPER-BUSSM...583434580&sprefix=bussman+rela,aps,137&sr=8-4

You can find them on ebay fully wired up for about $140:

https://www.ebay.com/itm/Universal-...per-Bussmann-ATV-UTV-RV-Boat-4X4/303323229872

 

Any reason in particular?

 

Gives an enclosure to put relays. Better protection against water.

 

I just like that the relays and fuses are in the box. I think it ends up a bit cleaner. Also, there is room for 5 relays circuits and 10 fused circuits. I (and I think most installs I've seen), use 5 of the fused on the relays. So you end up with a clean install with 5 fused relay circuits and 5 fused circuits. It's really just a personal preference I think.

 

8 or 10 gauge for a lower amp switch wire?...

 

The relay will tell you how many amps your switching at all you need to do is refer to a chart to see what size wire you need you can probably go at least 14 or higher

 

22~18 awg is all that's needed for the wire from the switch to the relay coil...

 

Right. First if he's tossing in a relay. Sorry, I meant as in you could go 14 and run it right to a switch, or check the relay to see what you'll need which what you specified would be fine.

For something like ditch lights you could just run it through the switch.

 

Was critical to get my old XJ lights replaced with way brighter lights and no fried switch!