Accessory Fuse Block and Cable Install in a 4WD - How to add 12v accessories to your vehicle

How to add a secondary fuse block to your vehicle to power accessories. I install a fuse block in my Land Rover Defender to power additional accessories and lights. I explain what you will need, and tips on the installation and reasons behind choosing the wiring I did.
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[@KR7PT]

Googled "How to install a fuse block" and this video came up as one of the first. I wish it didn't because I sat here waiting for you to wire up the fuse block, and you didn't.

[@sauce8277]

What a Easy-to-Follow, thoughtful video. I wish other people kept the viewer in mind as much as you did when you made this.

[@RoamingTheOutback]

Thanks James!

[@aussiepagan7173]

Finally. I straight forward and concise video. Liked how many redundancies you have with protection to the wires. Do it once do it right. Thanks heaps.

[@arthur.goldsmith]

This electrical overview is exceptional. I can't tell you how useful this has been. Thank you.

[@robrath31]

A handy tip to weather seal your exterior cables is to use conduit/tubing but NOT the split variety, get the un-cut tubing instead, fully sealed. Run the tubing the full length of the wiring to the terminals at each end and use 'glue-lined' heatshrink to cover the tubing and the terminal so all that's exposed is the ring/lug/spade terminal at each end. Provided you melted the heatshrink long enough for the glue to work and you covered any holes on the terminals (some are sealed, some are not) you have a super long lasting cable that won't corrode after many many years. Very good video :) Always informative :)

[@RoamingTheOutback]

Sounds like a good tip for those extreme environments. Never seen unsplit tubing before.

[@robrath31]

Just an example, solid or split available; www.ebay.com.au/itm/20mm-nylon-Flexible-Conduit-Cable-Tidy-Gloss-Black-1-10m/252308701276?hash=item3abec5405c:m:m-ic5Hq7JA6HLAD96sUqQYw - I was lucky and used to have access to it at my old job.

[@manfred9528]

instead of glue lined, would some dielectric grease at both ends prevent moisture draw? assuming no nicks or cuts are introduced into the system

[@billnicholson559]

Uncut tubing is great for a new install but impracticable for retrofit. Both types offer protection against abrasion and phsical damage to the cable which is the prime requirement. If water enters the cut type (e.g. when wading) it will seep out again. In practice it does a good job. I have used tens of metres of it my 4x4.

[@CORZER0]

That's a badass Land Rover. Wish they were as easy to come by here in the states. I'd pick one up in a New York minute.

[@balemonte727]

Outstanding, thank you for showing the math used to calculate it makes more sense that way.

[@RoamingTheOutback]

You're welcome mate. Thanks.

[@hellbringer42]

Bloody helpful video mate. Explained a lot for what I want to do for my LC. Thanks for putting in the effort.

[@RoamingTheOutback]

All good mate. Thanks.

[@aussiedrifter]

Very helpfull video for anyone doing their own elec work, as well as pointing out the mandatory through bulkhead use of grommets. It was a little funny as well when seeing the botchy older wires coming up next to the new work you were doing, I know this was older work probably not done by yourself but would have been a good "what not to do example" anyway mate good video as always.

[@RoamingTheOutback]

Thanks mate. Yes an old installation by a prior owner who used silicone around the hole as protection. Didn't actually notice that until you mentioned it! Will have to add it to the list of things to fix.

[@aussiedrifter]

No Worries Bret. ;-)

[@scenenuf]

You did an excellent job at explaining this my dude thank you!!

[@rogerthat2868]

So far I have the fuse block negative going to ground and the positive going up the rear end of the fuse block seller. Then flip the switch on and see if it works. Great video by the way.

[@billnicholson559]

Excellent video but one minor word of advice. Buy a professional quality crimping tool (i.e. with ratchet action and die type jaws). For a long time I used an amateur crimping tool and had periodic problems with terminals loosening under vibration. I have had no problems since buying the professional tool (I carry the simple crimping tool for repairs on the road). A further tip - buy a tool wth interchangeabl dies because you will occasionally encounter uninsulated terminals (esp. on Japanese equipment) which require a tighter bite. It's an excellent idea to use heat shrink sheathing at the terminals since iit acts as a bend restrictor and reduces the chance of flexural failure. This is essential for any cables attached to the engine which will fail otherwise. The common earth is a great idea for a new installation. If you are dealing with an old installation with local earths (as on my old bus) the best tip is to use star washers with silicone compound or grease to prevent oxidation of the contact area. Keep up the good work.

[@RoamingTheOutback]

Thanks Bill. I think I do have a pro crimper I've used on occasion but the basic crimper is the one I travel with due to its multipurpose design.

[@mikenewman9030]

Tuft Edu is u q 9 Ddg so e em ? ? Z rtf couple mt

[@magicnik8881]

Perfect timing, thats what Im gonna planing next weekend ^^ Thanks for the tips and tricks :)

[@RoamingTheOutback]

You're welcome mate. Enjoy your weekend.

[@Latindanceindia]

Super video Brett.. Some one didn't like ur VIDEO MAY BE JEALOUS..

[@RoamingTheOutback]

Thanks mate.

[@Reaper4367]

lol, its allways someone with a Tojo or cheep. lol.

[@kylemart2332]

Great work! Very informative video. Thanks

[@icedogsbustonowhere7178]

This video is awesome very thorough

[@The.2.Minute-Man]

A big thanks for your time and effort Like everyone side ( A big big help )

[@RoamingTheOutback]

Happy to help

[@novaworksind.7413]

Great video man! A lot of help

[@randelllmalavida]

Great job mate!!!

[@metaspencer]

great vehicle and nicely described ... I feel I can do my own install now. nice!

[@RoamingTheOutback]

Great to hear mate. Thanks.

[@leagueofshadows5133]

After seeing that board with all those numbers i went straight to yale website and submitted an application haha

[@eds4wdcamping]

You are going to love that oven I have one. You can even do a nice roast in it when on the road

[@RoamingTheOutback]

I've had a few goes with it thus far and have cooked reasonable roast veggies in 3 hours. What times are you getting? And do you have any tips how to get the best out of it? Thanks

[@eds4wdcamping]

Pre heat when on the go one big thing oven bags and foil trays the oven will keep heat in when turn off for some time. 3 hours sounds about right for beef Ed

[@magniankh]

Voltage drop is negligible on short runs, especially for DC power as it experiences less loss over distance. A distance of 20' of wire won't make any difference concerning voltage drop, just simply size your wire based off expected amperage. I'm an electrician and on new installs we don't calculate voltage drop unless we start running wire more than a few hundred feet. The Blue Sea fuse block that I bought has 6 terminals rated for 30a each, with a total rating of 100a. Size 3awg wire can handle 115a, but my expected load is only about 70a maximum, with everything running at full capacity which will never happen. Unless you have multiple light bars and you know for a fact that you will max out the amperage on a fuse box, you could probably run wire as small as 6awg. Clean install nonetheless, but it doesn't need to be this complicated. Feed 100a with 3awg and call it good.

[@edwardh1003]

In the first part of the video you talk about adding a circuit breaker between the battery and positive cable to prevent electrical fire. If I understand it correctly, the first line of defense in case of malfunction is the fuses in the fuse block and the protection after that is the circuit breaker which cuts all power to the fuse block and all accessories. Is this correct?

[@RoamingTheOutback]

Yes. You must have protection of the positive wire from the battery in case it shorts from the battery to the fuseblock. Then the fuses in the fuseblock protect the individual circuits from the fuseblock to the appliance. I once had one of my work cars nearly burn down because the guy who installed the accessory wire to the battery didn't add a fuse next to the battery. The wire shorted and the whole cable went up in smoke, melting its full length.

[@edwardh1003]

@@RoamingTheOutback Wow, that's awful. Thanks for the reply.

[@Overlandingessentials]

Good job Bret 👍

[@WogChilli]

R = (ρ x L)/A R = resistance measured in ohms ρ = resistivity of the conducter (ie 1.68x 10^-8 ohm m) measured in ohm meters at 20 degrees C L = length measures in meters A = area measured in millimeter squared (not to be mistaken with mm diameter or circular mils) so a 5 meter length of 2.5mm^2 cable would have a resistance of (1.68 x 10^-8 x 6)/2.5*10^-6 = 0.0336 ohms Then you can multiply the ohms by 2 because there are 2 conducters (positive and negative) 0.0672 ohms Then you multiply by the amp draw and that will give you voltage drop. Using 12.6 volts as an example 0.0672 x 12.6 = 0.85 volts So in 12 volt circuits you want to keep voltage drop under 5% so you can calculate voltage drop as a percentage 100 - ((battery voltage after drop x 100)/battery voltage before the voltage drop) 100 - ((11.75 x 100)/12.6) = 6.75 % voltage drop, so in this case you would consider going to a lower gauge (or higher mm^2) cable

[@WogChilli]

My mistake on voltage drop. You multiply the resistance by your current load Ie if that's the case 0.0672 ohms x 12.6 amps (this is where I made the mistake) would = 0.85v drop.

[@peewee007654321]

Thanks for the video, I too want to run aux equipment in the back of my Isuzu trooper. I wanted to know which gauge cable to use. 👍👏

[@pedrogonzalezm.2609]

Congrats and thanks for the vid~!

[@RoamingTheOutback]

No problem 😊

[@andufuse640]

good lesson. i make car fuse and fuse tap .

[@Paumonsu]

I didn't know Tony Hawk was into offroading

[@RoamingTheOutback]

haha.. guess I do look a little alike from the right angle.

[@itolond]

Looking at setting up a dual battery in the 110. I have most of the wiring sorted on paper, however having not done this before a bit lost on the starter/Aux battery isolation wiring setup. As I understand th purpose it to isolate the starter battery to maintain starting capability whist the Aux/Acc battery can be discharged etc... I have acquired a projects DC/DC unit to manage this ... all good here. Where i am lost is actually how to isolate Acc power. On the Defender there is power to IGN which is is used for both starter primary and accessories, so how does one isolate AUX power with only one connection for power to IGN?

[@RoamingTheOutback]

hi mate. I don't quite understand your problem? But the secondary battery should be separated by the DC/DC when the ignition is off. All accessories should be wired to the second battery. With the engine on, the DC/DC should connect both batteries for charging. With engine off, they should automatically disconnect so there's no chance of draining the starter battery. Check your manual for your DC/DC to ensure it has an auto-disconnect function.

[@itolond]

after some more research i think i have resolved this question, I was using Boat battery isolation as the model where all but the primary is isolated (e.g. no acc. loads a all) this is a bit of a challenge for a 4x4. Now i understand slect Acc loads should be the target for Aux batt isolation not all... My approach was of base

[@billprestonesq88]

do you run the oven through the fuse block? I know it is recommended to directly wire the ovens to the battery .

[@RoamingTheOutback]

Through the fuse block. This oven only draws 6 amp.

[@drewsprinkhuizen9721]

hey mate so correct me if im wrong, so if i have a fuse box that has a max of 120 amps say, i would need to use 4 awg wire with a 125 amp fuse ONLY if i plan on using all slots at the max amp output? other wise if i plan on only using say 2 fuse outputs at 15amps then 10 guage with a 30 amp fuse is all i would need? just trying to get my head around that

[@robertgough8347]

I have a Toyota Hilux tipping ute. Do you have any idea where the fuse box may be located for the tipping device?

[@RoamingTheOutback]

try contacting the company that did the conversion.

[@boogalookid9562]

thank you

[@michaelleigh2446]

great job mate, but i'm a complete numpty when it comes to elecs, so to show how to connect to 12v system would have been useful. hoo roo

[@billprestonesq88]

thanks mate

[@craiggambetta694]

I cannot believe how many Amps a laptop draws, also how many Amps does that oven draw?. Great video by the way....

[@RoamingTheOutback]

My laptop is a workstation, so very power hungry graphics card. 6-10 amps depending on what it's rendering. The oven is 6 amps. Thanks Craig.

[@craiggambetta694]

@@RoamingTheOutback That makes sense if your rendering graphics. i thought you may have been mining for Bitcoin.... 6 Amps is pretty good for the oven i think, as long as it doesn't take 2 hours to warm a cup of water...

[@RoamingTheOutback]

2 hours cooks roast veggies and meat. 2 to 2.5 hours bakes a damper. View my cooking videos to see.

[@mattoriental]

Nice work as always Bret - what size circuit breaker did you use (would have been good to see how you wired it up)

[@RoamingTheOutback]

A 60 amp breaker though probably would have preferred a 50 amp. Sorry didn't think to show that part, but just 2 ring terminals, one on each end screwed down. Same connections as on the fuse block.

[@Toshiro7777]

Great vid. Thanks!

[@RoamingTheOutback]

Thanks for watching.

[@brunoburtoni8479]

does an auxiliary fuse block affect the orignal wiring and fuse box as its hooked it up via the ignition ?

[@RoamingTheOutback]

No, unless you mess with the original wiring. My fuse block is wired completely independently. You could make it live with ignition on if you add a relay for the positive feed.

[@Rampage287]

Thanks alot brett, very thoroughly spoken and easy to understand im goin to run basically the same system i think 🤔 just wondering for all your accessory sockets what size fuses did you run on each input? (Eg 10a for 12v socket, 20a for fridge etc?)

[@RoamingTheOutback]

Thanks Jack. 10a for the sockets and 5a for the fridge. The Engel only uses 2.5a max. 10a for oven. 5a for lights and usb.

[@Rampage287]

Roaming The Outback Ohh wow I expected more from the fridge but thats even better then hey, thanks alot mate for the very useful info, cant wait for future videos brett 👍

[@willcowell8197]

Impressive! You know your stuff! After figuring that out how long did it take you to install?

[@RoamingTheOutback]

I had to do it over the space of a few weeks as I found time. Otherwise, probably 6 to 8 hours if everything runs smoothly.

[@themancambodia]

Do you have a link to that ST fuse block holder?

[@BillyS4208]

Hey I'm planning of setting up some 12v sockets and usb sockets up on the backboard of my tray (trayback ute) from my second battery with this same fuse box and wiring but the box and wires are going to be on the outside of my car (inbetween backboard of tray and the cab)... will they be okay outside of the car? They wont be easily knocked or hit or anything but will be exposed to the weather and dirt....

[@RoamingTheOutback]

Not a good idea to have it out in the open exposed to water and dirt. You need to keep the fuse box clean or the fuses and wires will corrode. Maybe purchase an electrical box with grommets to fit it inside that for protection?

[@williamwalsh9615]

So for the B&S =0.48v. How was the 3.5% loss figured out?..... Can't do basic maths at the moment

[@Deckardrick007]

Could this be done on a Series 2A?

[@RoamingTheOutback]

Can be installed in any car when you want a secondary fuse box.

[@fabianelliott96]

i wouldnt run the power wire through the floor, now the cabin is not waterproof

[@RoamingTheOutback]

Haha. It's a defender.. it's never been waterproof.

[@fabianelliott96]

Fair enough haha

[@Bassillixx]

10:54 It looks like the insulation is starting to tear away from where the cable joins the far socket.

[@RoamingTheOutback]

yes that's an old cheapy camp light. Still works fine.

[@trd_tv1311]

12 AWG work as long as thier 12v qccessories and fires for relays

[@supnacho7454]

Hardcore

[@kellybrown6988]

Felt like I was more in a math class than watching someone install wires and doing electrical stuff. Did not see any install segment, just clips of the already finished product.

[@RoamingTheOutback]

Thanks for the feedback Kelly. I didn't see the point of showing much of the install, as its nothing more than drilling a few holes and bolting the fuseblock in place. The maths is the more important thing. You get that wrong, the car could burn down. I'll keep it in mind though for future electrical upgrade videos. Thanks.

[@tomjohnson1110]

Can't you buy charts to calculate wire gauges. Because listening to your calculations gave me an almighty headache .lol

[@RoamingTheOutback]

Yes, most likely, though they are rough guides, not exact for your spec cable. They will suffice for most installations.

[@ninoleicher2660]

Naai

[@cdizzle5495]

I don't maths.

[@RoamingTheOutback]

Use an app.. it's easier.

[@420killahkush]

I love your TDI!