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.
Duplex wire consists of 2 separate conductors in a single sheath and will be the main type of wire you will use for your 12v Branch Circuits. Size will depend on the load and distance that the wire will need to run. The wire linked is high-quality marine-grade wire with 105° C Insulation ratings.
Triplex wire consists of 3 separate conductors in a single sheath and will be the type of wire you will want to use for 3 way switches.
For DC applications; Red is usually "Positive" and Black is usually "Negative". It's difficult to source triplex wire with the proper wire colors, so the proper way around this is to put a 1" piece of RED heat shrink on the Green and Wire wires at each end of the wire to denote that they are "Positive" wires.
Size will depend on the load and distance that the wire will need to run. The wire linked is high-quality marine-grade wire with 105° C Insulation ratings.
WAGO Lever Nuts are a great way to connect 2-5 wire together. The Wago 221 series can accept wires as big as 10 AWG and as small as 20 AWG and are rated for up to 30A.
This is a 12V Single-Pole-Single-Throw switch necessary for turning 12V circuits like lights or a water pump.
This is a 12v Single Pole Double Throw on-on switch necessary for 3-way switches a.k.a. lights that switch from 2 separate locations.
This fuse holder is used for switch panels where smaller wire is used downstream of the switch panel than upstream of the switch panel. This particular fuse holder holds 4 fuses and is, therefore, able to protect 4 circuits coming from the same switch panel location.
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 (https://www.amazon.com/gp/product/B01C4UBMY6/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1).
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
Steven Wolfe
Wednesday 17th of March 2021
Hi Nate, I saw your video on building a custom buss bar a few weeks ago and have gathered all of the components to proceed. I saw your recent posting on that video warning that you no longer recommend using this plan. I have a Renogy 12v 3000watt inverter/charger and 3, 12v 120 ah Lifepo4 batteries that I want to install in my RV with 30a service. I was all geared up and have begun to build this. You've stated that there was a problem with inferior fuse holders. Do you have any other possible suggestions for me to improve this design? Going with the Victon Versa (or whaterver it was, am on my phone and forgot the exact recommendation) is not really feasable for my budget. Can you offer me any other options? I do plan to operate my upgraded equipment conservatively. Thanks, Steve Wolfe
john k
Wednesday 10th of March 2021
hi nate-
although it took me a couple days of thought, the solution was very simple- i had the polarity of the switches reversed. well, DUH! two of my five lights are now working and i guess i have to troubleshoot the other three. this weekend's mini-project!
until next time...
jk
john k
Monday 8th of March 2021
hi nate
have a question about switches
i purchased all the stuff for wiring my van through your list, carefully did the wiring. it was a tense and exciting moment when i installed the battery and turned on the power. No smoke! eureka!
i installed 5 12v plugs through the distribution box, tested them all, they all worked. installed two reading lights through the distribution box, tested them, they worked. bought a 5M light strip, cut it into five pieces, tested them all on a separate battery. they all worked. installed them with the SPST switches on your page. tried to test them. every one of them blew a fuse
WTF? any suggestions as to what i do next?
all the best
john kumiski
Nate Yarbrough
Saturday 13th of March 2021
I saw through a later reply of yours that you were able to troubleshoot and figure it out. Nice work!
Bradyn
Tuesday 23rd of February 2021
I am getting ready to rewire my 1986 Airstream Sovereign and I keep having a thought that I can't reconcile. I would like my batteries to be able to charge off of my truck while in transit in order to keep the fridge running on longer road trips. How do I tie that into the charging system on my Progressive Dynamics PD4045CSV?