Fuse box, Relays, Switches... help a dummy out

Hello, it's almost Taco Tuesday and I need some learnin before I can enjoy any tacos.

Here is my question cause I have been looking for about 30 minutes and cant find a good thread...(NOTE: I am a complete electrical dummy. I can replace piston rings, but cant replace a light bulb)

Anyways, I want to add a few lights to my 2018 Off-Road Tacoma(Ditch, rear facing environment, and light bar), and don't understand the process from going from loser to pro. The main question arises from understanding relays. I want to use this blue sea system (Link: https://overlandequipped.com/collec...for-3rd-generation-toyota-tacoma-2016-present ) that will be wired into some cali raised buttons on their three switch mounting bracket where the coin cubby is currently.

I know you go from battery to breaker to fuse box, but from there I am lost. What is the relay doing if I have switches inside my cab? Can someone please explain to a dummy how I go from fuse box to lights using in cab switches? Do I need relays for Baja Design/Rigid lights? Do I need to go back to school? Do I even deserve Tacos????

 

The purpose of a relay is to keep the higher amp/current from flowing through the switches in the cab. Generally the switches in the cab are designed for low(er) current. The relay is a high(er) current switch. If you put high current through a device designed with a low current rating, chances are it will burn out. So you turn the high current switch (the relay) on/off with the low current switch in the cab.

 

So if I have this blue sea fuse box, and I want to go from that to a relay to my switch, to all of these lights... do I need a relay for every light? Seems like a lot of extra wiring, and random relays I now have no idea where to put.

 

https://www.explainthatstuff.com/howrelayswork.html
https://www.12voltplanet.co.uk/relay-guide.html
https://components101.com/switches/12v-relay

Use relays so you don't overload switches and burn your truck down.

 

Where do you put your relays? Makes more sense now, but is there a nice relay holder somewhere out there? Do I need a relay for every light system or can I combine rear environment/ditch lights?

 

Mine sit beside the fuse box;


CaliRaised makes a holder;
https://caliraisedled.com/products/2005-2020-toyota-tacoma-4runner-bolt-on-relay-holder

You want a relay for each use; ditch lights have a relay, driving lights have a relay. If they were all on the same you wouldn't be able to use them independently.

 

You can combine devices/lights in logical combinations upto the rating of the relay. e.g., light1 is 5 amps, light2 is 3 amps. Together 7 amps. As long as the relay is rated at greater than 7 amps you can control both lights through one relay. Note: I would add some head room to the hypothetical relay rating.

 

You most likely want to look into a fully integrated unit such as a Bussmann RTMR or an ssVEC unit by Eaton.
https://www.tacomaworld.com/threads/ongoing-small-batch-bussmann-rtmr-5relay-10fuse.400458/

https://www.tacomaworld.com/threads/diy-build-and-install-a-bussmann-rtmr-fuse-relay-block.399454/

 

Someone posted a cool product that I cross posted on the AUX fuse panel thread over here.

https://www.tractorsupply.com/tsc/product/traveller-4-way-wireless-remote-control-system


I went for the OE fuse block bracket, but added a

$76 Blue Sea Systems 7635 m-LVD Low Voltage Disconnect

Low Voltage Disconnect so it doesn't drain my battery as seen here and here.

If you do use the bracket, be sure to check out the conflict with the brake wire here.

 

https://www.tacomaworld.com/threads/diy-build-and-install-a-bussmann-rtmr-fuse-relay-block.399454/

A very informative and helpful article. You dont need to go as deep as he did with buying all the separate pins and such since Amazon has kits/everything these days.. do some research. Fun little project

 

leave it to the aftermarket installs to screw it all up

 

I know it's all probabaly super confusing but once you learn the basics(relay pin out/function, basic fuse layout, grounding) it's all super simple after that. I personally didnt like anything aftermarket, if something failed it wasnt changeable or fixable you had to buy a whole new unit. So I built my own power distribution/fuse box. They're currently arent any fuses in this box because I have to measure the output of my accessories but you get the idea hopefully.