Blue Sea Fuse Block - Newb, trying not to electrocute himself

Some of my accessories only have positive leads, Do I have to connect a negative to the fuse block in order for them to work?

I think I've got the right idea here...am I missing anything? I see in some pictures that people have the negative attached to the ground and then to the negative battery terminal. Is this necessary?

http://www.pelfreybilt.com/product/fuse-panel-automatic/

$31 Blue Sea Systems 5026 ST Blade Fuse Block 12 Circuit with Ground and Cover, 100 Amps

Blue Sea Systems ST Blade Fuse Block - 12 Circuits with Negative Bus & Cover

$35 Blue Sea Systems 7087 285 Series Thermal Circuit Breakers, Panel Mount, 48V DC, 100A

Blue Sea Systems 285-Series Panel Mount 100A Circuit Breaker

 

I'm not sure why the forum post wont let me save this with spaces showing the wiring setup...I'll post pictures tomorrow.

 

I'm working on the same setup. The positive runs to the circuit breaker +, the output from the circuit breaker runs to the + on the fuse panel. If your accessories only have positive leads, they are self grounding in some way, usually through the mounting point. Make sure you ground the fuse panel well.

Where are you mounting the circuit panel and the fuse block?

 

If you don't understand basic 12v wiring then why are you doing it? Not trying to be a dick but its simple but can destroy some extremely expensive stuff.

I have the same fuse panel for my enclosed trailer. It needs a suitable positive feed and a suitable ground. Once you have a good ground you can either run a wire all of the way to the neg on the panel or just a solid chassis ground for your accessories. I hope you understand what I mean by chassis ground.

 

https://www.tacomaworld.com/threads/rondogs-camping-build.416256/#post-14303592 is how I set mine up.

1. run main + from battery to circuit breaker to + on fuse block
2. run main - from battery to fuse block

You can ground your accessories anywhere. It doesn't have to be on the fuse block itself. Most of my lights I grounded somewhere to the frame.

If these accessories are going to be on a switch, the + coming off the fuse block should go to a relay...specifically the 30 pole on the relay and the + from your accessory should go to the 87 pole. I used this diagram when I wired up my lights and it helped explain a lot. I was a newb to electrical too.

 

1. I like projects and I'm learning as I go. I have a bunch of accessories that I'd like to tidy up and rather than have a fuckton of add-a-fuse connectors hanging off my positive battery terminal, I'd like to keep them all in one nice place. I've got a relatively decent idea of what I'm doing but some noob questions that I wouldn't know the answer to unless I ask. So I'm asking. Ain't no shame.

2. I know what is meant by chassis ground, but I want to make sure if i need it for every accessory, or if I can just run a wire straight to the Blue Sea positive and plop a fuse in the block, it sounds like the answer to my question is yes as long as I've got a good ground.

 

Everything has to be grounded one way or another. What accessories do you have that seemingly don't have grounds?

 

Necessary - no.

Desirable - yes.

As long as the fuse box is grounded, you can use its ground terminals for your accessories. Grounding to both the frame/body and the negative battery terminal is a nice-to-have to minimize the possibility of drawing "too much" current through whatever frame/body ground you use.

Also, before doing any electrical work whatsoever, disconnect the negative terminal on the battery. I like to place a folded, dry towel/cloth on top of the disconnected terminal to ensure nothing accidentally comes in contact with it. When you're done your work, that's the last thing you reconnect.

 

For instance, I have an O+ Reference 450Q that is grounded to the floor under the drivers seat, and has a positive cable sent through the firewall to the positive terminal. No negative cable. I also have bed lights that are grounded to the frame but also just have a positive cable and an add a fuse.

 

The cable grounded to the floor is the negative

 

Subd. Have these ready to go also.

 

Electricity will always follow the easiest path. Sometimes we just have to make sure it goes where we want and not somewhere we don't.

In terms of this panel you can take it direct to the panel or if that is more effort than it is worth and you can find a good ground close by then go that way. So you are correct in thinking so. On some items I would go direct to the panel if I felt rust could be an issue over time and I might lose that good chassis ground.

One BIG consideration is wire size. Based on current you need wire sized appropriately and fused accordingly once again. There are a ton of online charts available that will show you the correct wire size based on voltage and amperage. I would suggest you check those charts first before ordering wire or hooking stuff up.

Here is the first chart I googled:
https://www.tessco.com/yts/industry/products/itm/automotive/get_wired.html

 

That accessory's "negative" cable is the ground. You'll be fine to leave the ground as is, and run the positive to the new fuse box. Check how much current that amp will use and get an appropriate fuse.

 

You can't electrocute yourself on your truck without significant planning, schematics and a bucket of water to stand in. You can however let the "magic smoke" out of sensitive electronics if you don't know what your doing. Everything in automotive wiring has a power ( positive ) a ground ( negative ) and a signal or load.

 

I just installed that Blue Sea fuse block in my boat. Its not really the correct type for a car because almost any metal point in the car is a Neg Gnd connection. That posted fuse block has a Neg terminal and bus connections which you will not need. A lot of boats need that type of fuse block because they are mostly made of fiberglass and you cant use the hull as a Gnd. Im pretty sure Blue Sea makes a more compact version with just a POS bus connection. Also, remember to get fuses rated for the wire gauge and length of run, NOT the accessory. The purpose of the fuse (among other things) is to prevent the wire from causing a fire by acting as the fuse.

 

Absolutely WRONG.

You size the fuse for the accessory for its protection. You size the WIRE for the fuse and the accessory depending on length of wire run. If you size the fuse for the wire only you can destroy your accessory if there is a short or over current situation. Always start your circuit based on the accessory. Then determine fuse and AFTER that determine run length. Based on run length and amperage you then determine wire size. By doing it this way you allow the circuit to feed the accessory with the proper amount of amperage for it needs (and not blowing fuses to the point the accessory doesn’t work when you want it.) It also provides protection for the device and the wire will be sized that the fuse will blow before the insulation is compromised in the case of a dead short.

You wire as above for hardwired devices. In residential wiring you fuse / circuit breaker for the wire as plug in devices are constantly changed.

 

Ok sparky

 

Bit of a thread revive but Iv been trying to find the lengths of the battery cables that connect to the blue sea fuse block to the circuit breaker to the battery. I’m going to order some custom length battery cables from power trays. Do you happen to know the lengths?

 

@txtaco87