Please check my diagram

Does this wiring look good? I want to get one of the many generic aux fuse panels (correction: switch panel kit) for some lights, no big draw. I want to power it from the ignition though, not the battery.

My next question is, any suggestions what fuse to tap?

 

100 amp fuse? What are you running off of it? Almost zero point of even having a fuse if youre gonna use one that high in a vehicle haha.

 

Are you planning to run a "generic aux fuse panels" or a "switch panel kit"?

Your diagram suggests to me that you plan to run up to 100 amps through a Bosch-style relay. Is that your intent?

 

That looks correct to me. Just wanna make sure you have a relay that can handle the current, which aren't hard to find.

 

Sorry for the confusion. A switch panel kit, a Bosch-style relay, and a circuit breaker like this one (for the 100A fuse):

$33 Bussmann CB185-100 100 Amp Type III Circuit Breaker

https://www.amazon.com/Bussmann-CB1...s=100+amp+fuse+bussman&qid=1572213594&sr=8-12

 

I would figure up what the amperage draw of whatever you wanna run off the circuit is, then find a breaker that suits it better. 100 amps is a lot. The wire will definetly melt at that amperage before the breaker is gonna trip. Unless youre running like 4 awg into the cab.

 

I’d consider wiring the relay a constant hot rather than an ignition keyed source. That will give you the flexibility to run the lights whenever you want rather than only by leaving the key turned on in the truck.

 

The relay will be about 1 foot from the battery, and the 100 A circuit breaker will be between them. Basically, I would have a 1 foot long 4 awg cable, between the relay and battery. The relay will be on top of the switch panel box. Shouldn't be a problem with such a short run.

I know... I'm still thinking about this.

 

What are you running thats gonna pull anywhere near 100 amps? Thats so overkill that it could be dangerous. Find out how many amps the load is gonna draw and utilize an appropriately sized breaker. If it draws 25 amps, use a 30 amp breaker for example.

 

No it’s not. If anything it’s more safe. Once you start adding things up, i.e. fridge, lights, compressors, etc. it’s best to err on the side of overkill and have a wire that’s too thick as opposed to too thin. Plan for worst case scenario of all things running at once and add a little cushion.

 

So we're assuming "Engine Fuse Box" is ignition switched, right?

 

I'm not sure how you're getting that a higher current fuse/breaker is safer. I'm all for thicker wire, but the fuse should be sized just a big bigger than the load you want to run, and then upgraded as additional loads are added.

 

Im not reffering to wire, Im talking about the breaker size. If his load is only gonna draw 50 amps for example, why would he need to utilize a 100 amp breaker? Thats a ton of room for error and stuff to start smoking. ARB fridge doesnt draw anywhere near that per this thread . OP, again, what are you planning to run?

 

If the fuse/switch panel he is running has individual fused circuits (like a Blue Sea) I wouldn’t be concerned because the individual outputs are protected at that point. Even if it’s something like a Switch Pro he can wire each output fused independently appropriate to its draw. The 100amp breaker is essentially just protecting the fuse/switch panel from failure.

 

Agreed.

I think we need more schematic than will fit on the post it note he posted.

 

I want to run some lights, maybe a fridge, and that's about it.

The "engine fuse box", is, well, what it says. The fuse box in the engine compartment.

The switch panel has individual fuses. I'm thinking of using something like one of those two, but being triggered by the ignition and not directly the battery:

Suitech Universally Adaptable DC12V LED 6 Switch Panel Electronic Relay System with Circuit Control Box - Wiring Harness Kit for Any Vehicle - Power up to 6 Aftermarket Lights and Accessories - 600W

https://www.amazon.com/dp/B0739R9SQ...colid=V91DIF3U9MZD&psc=1&ref_=lv_ov_lig_dp_it

Voswitch Universal 6-Switch Pod/Panel in Blue Backlight with Control and Relay Box Fits Truck,UTV, Jeep and Boat(Comes with 12 Switch Covers)

https://www.amazon.com/dp/B07DX63XK...colid=V91DIF3U9MZD&psc=1&ref_=lv_ov_lig_dp_it

 

Yeah what he said. Each circuit is fused on its own so the large 100A fuse/circuit breaker is for say if you get in a front end collision, and that 4 gauge wire breaks free. Now instead of being able to freely short out on something metal and potentially starting a fire, the fuse should prevent that.

 

Please check my diagram. That’s what the blonde said to the gynecologist.

 

I like your idea to have the power supply switched with the accessory circuit. But isn't the Bosch Relay only rated for 40 amps? Your probably going to need a solenoid for this.

 

True... something to keep in mind when calculating the load