Electrical mods, relays and fuses

So I bought a relay/fuse box. It's a nice unit, waterproof, and holds 6 of each. However, I was laying out the setup today and got thinking, am I going to actually need a relay for anything? So far, all I can think of is my Hella 500's. They'll pull 18A. Other than that, I'll have my KC fogs (1.6A), my fridge (3.75A), my shower pump (.6A), and I just can't think of any other high wattage items. Any other lights I might get will be LED which are low draw. So, am I wasting my time trying to do this relay box, or should I just do a fuse box, properly sized siwtches, and keep it simple??

 

Even though they are LED I used a relay on my rock lights and ditch lights just for piece of mind.

 

Always isolate especially auxiliary items. It's extra insurance. It keeps hot wires out of the cabin.

 

Piece of mind that you won't overload your wiring? (I know, stupid question, but wiring/electrical is NOT my thing)

 

Not really worried about the wiring more with just proper circuitry in my mind and protect the switch somewhat.

 

Gotcha. I'll stick with the relay box then

 

I just installed a lot of LED's on one truck and each set came with their own harness. Every set used relays. You're correct in that you don't really need them, your one set of higher draw lights you could use a switch that will handle the current, and the others use much less current so it wouldn't necessarily be a problem. The selection of low current switches is much better, as another commenter stated the relays will keep the higher current out of the cab, and it will be more reliable with relays in the long run.

I also noticed on a different truck that I installed 2 sets of LED lights on that the premade harnesses came with 30 amp fuses but right on the box the lights came in it stated their current draw was 3.4 amps each. Idk why they came with a 30 amp fuse (yet).

 

The other nice thing about relays is you can use pretty thin wires to run the switches, and then keep the heavy stuff just from battery to fuse box. Makes it easier when you're pulling wires and such.

 

Also having a relay to pull out and measure the pins gives you a convenient place to check the load and switch if you need to troubleshoot.