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12V Camper Branch Circuits – Parts & Components

12V Camper Branch Circuits – Parts & Components

This list will show you some of the more common parts and pieces necessary to wire all of the 12V branch circuits in your camper.

Jack B

Sunday 28th of November 2021

Hi Nate, Sure would like to see a products page or YouTube covering wire management. The wire diagrams look nice and neat. I'm not sure what wire holders or wire channels to use on all the different wire sizes and wire runs so it doesn't turn into a big pile of spaghetti. Any chance of some tips and products to help manage the wiring in a neat, organized way? You seem to be the best guy for that job.

Nate Yarbrough

Wednesday 1st of December 2021

Great idea! These are by far my favorite for 90% of wires: But proper wire management always starts with a good plan. Without a good plan and diagram, it gets out of hand in a hurry. The diagrams I have at are designed so that the parts can be laid out as shown so that the wiring can end up as shown as well.


Tuesday 23rd of November 2021

First, thank you for doing a high resolution diagram... which I purchased bc my eyes are not what they once were. (The diagram I am using is for a 2000w inverter, 200-400ah, and 200-520 watt solar)

I am following every part exactly but have a question regarding the 2000 inverter charger. I hope to add more solar and more batteries at some point. Can I purchase a 3000 inverter charger now? I rather not be forced to repurchase in the future so what items can be used in both set ups? Have I made a mistake following this diagram rather than the 6 battery diagram?

Also I had no idea when I got into this that it would be so expensive to run the few things I want to run in my little short bus... but my goal at some point is to be able to run a roof top a.c. unit so I am trying to prepare for the inevitability of 6 batteries.

Thank you so much for your blogs posts and videos and for having a following that asks great questions of which I have also learned from.

Thank you in advance for your thoughts. -Siva Aiken

Nate Yarbrough

Wednesday 1st of December 2021

Nope. Adding a bigger inverter means more batteries (200Ah minimum vs 400Ah minimum as well as bigger wires, lugs, fuses, etc.

Ryan Giblett

Monday 25th of October 2021

Hey Nate, love your blog, really appreciate all your tips. Quick question, what's your preferred way to make a 3-way connection, a so-called "T-junction"? (I refer to when a wire branches off from another, ie. when you're hooking up lights in parallel.)

People talk shit online about T-Tap connectors, saying either that cut too far or too little into the surrounding insulation. Either way they're criticized as being unreliable.

Soldering seems to be the way to go but apparently isn't recommended as much in vehicles. This is because they have a lot of vibration. Apparently over time the ends at either end of the solder can break because the solder itself is so rigid.

Lever nuts are included in your provided diagrams, why?

Thanks, Ryan

Nate Yarbrough

Wednesday 1st of December 2021

Lever nuts are the most user-friendly and reliable option out there.


Thursday 23rd of September 2021


Do you have any recommended / affiliate links for the following? I feel like you must, but I just can't find them!

-USB Outlets (C and standard) -Combo 12v USB Outlets -Light Switch and Dimmer (Does the dimmer and switch need to be separate units as indicated in your 12v wiring diagram?)

Lastly, I am following your 2000w Inverter Charger Budget Friendly Wiring Diagram, which shows a single red wire going from the shunt to the busbar. I presume this is so the battery indicator can function. I purchased this one:

Anyways, it's the only wire in the diagram that you do not have a sizing for, why is that? Do you have a recommendation based on the info I have provided?

If it helps, I am currently running 320W of Solar and have 1 100amp Lithium battery and will add a second if needed.

Thanks again, Keaton

David R

Tuesday 30th of March 2021

Hi Nate,

First of, thanks for the great site. I purchased your 12v wiring diagrams and had a question on the 12v powered from a single location with the 4 Common Circuit ST Blade Compact fuse block [#4045] (Page 6/9). I am running 4 similar LED circuits with the PCA Electronics compact dimmer switches (

Question: My intent was to have a master switch between my panel and and the 4045 SD blade so I can simply make sure all the lights are off if I leave the van.

1. Do you recommend a switch for this location and should I use a different SD Blade fuse block that what you have listed on your site. 2. Can I consolidate the negative to the lever nut shown and then to the negative on the new switch and then to the panel? 3. Based on the above, should I be using a different dimmer.

Thanks, David