The Cameo Camper Renovation: Wiring a Vintage Camper From Scratch
Newer, Related posts:
If you’re having any weird electrical issues (like some lights working while others don’t, inconsistent electrical), you may have a bad ground. Check out how to ground your camper here.
Since this post, we learned how to modify our 120V accent light fixtures to be 12V. Check out how you can turn any 120V light to 12V for energy savings!
Disclaimer + safety
Please please please always make sure when you’re dealing with electrical that you turn ALL of your power off, wear the appropriate PPE (personal protective equipment) and use a reliable voltage meter to triple check that your power is actually off. You never ever want to find out the hard way that you guessed wrong.
If you missed it, we recently shared how we wired the exterior electrical, though it was more focused on what/how we installed the fixtures and less about the actual electrical hookup (because we failed and decided it was better for our sanity to sub it out to the pros). This post will be very detailed and breaks down exactly how we setup our entire electrical system – the one that pulls shore power from a campsite/house/generator, charges the battery and feeds power to all of the electronics. There are a lot of considerations and because each camper’s needs is unique, as we researched we found there are multiple ways to set it up. This is what worked for us.
I should preface this by saying in no way are we electrical professionals and until extremely recently we knew relatively little about it, outside of how to install ceiling fans and lights at our house. I will warn you now: camper electrical is an entirely different beast. This is what worked for us and our specific needs, including running wiring/powering all of the following:
A window air conditioning unit, because we live in Texas – this was the biggest power suck and consideration for needing so much power. If we didn’t want an A/C unit we could get away with a lot less.
An electric water heater tank for the shower only (the sink will not have hot water)
The water pump
Electrical outlets – 5 standard American outlets and 3 USB only outlets
Interior ceiling and wall lighting
Induction stovetop
*Note: As of now we are not installing propane to run any of our appliances so everything we plan must run off our electrical system. We are not installing a refrigerator at all, which is a common trailer appliance that uses propane.
A quick lesson in power
There’s a whole lot that goes into understanding electricity, and even more for a camper/travel trailer since it runs two different types of electricity – AC, or 120 Volt, and “low voltage” 12 Volt DC power.
While we’re at it, I want to clear up something confusing we kept running across.
Why do some sites say 120V while others say 110V (or 115V)? Are they interchangeable or is there a difference? What gives?
I’m so glad you asked. From what we can find, it’s all basically the same. 120V is the AC voltage on a single hot wire in your home, and with resistance in the wiring in your house it will likely have dropped to 115V by the time it gets to the appliance you are powering. Add to the mix a long extension cord and it could even drop to 110V. We’ve also read it could come down to age – of the line and the person referring to it. It seems like 110V is a carryover from “the days of yore” (according to one source), and old school electricians are often the ones who still call it that. Nowadays, modern house electrical is 120V and that’s what the electrical youths call it. In an effort to stay hip and with it (tak-a-tak-a-tak-a-tak-a…) we’re going to call our AC power 120V. Onward!
iPhone charger with “cube” converter
The easiest way I can explain AC vs. DC power – and what finally made the two types “click” for me – is how my iPhone charger works. The charger cord plugs into your phone, and on the other end has a male USB plug, which plugs into a small white cube that then plugs into a standard electrical socket. The little white cube is a baby-size converter that converts your home’s 120V AC into low-voltage 12V* DC power.
{Same can be said for Mac laptop chargers – the thicker cable plugs into a standard wall outlet, drawing 120V power from the wall. Then the power travels through the converter, changing the 120V AC to 12V DC, which makes it possible to charge the computer.}
*(Ok, since the original posting I learned technically it converts it to 5V … but for all intents and purposes let’s call it12V just for this example.)
12V DC vs. 120V AC power
Generally, the 12 Volt DC electricity powers our necessary items (lights, smoke detector, water pump that carries water from the fresh tank to the shower, toilet and faucets, etc.). Basically anything that requires a battery to run – a cell phone, computer, etc., and therefore the USB-only wall chargers – is considered “low voltage” 12 Volt DC power.
On the other hand, 120 Volt AC powers more of the “luxuries” of an RV (air conditioning unit, water heater, etc.)*.
Because shore power comes in at 120V, we chose to split up our USB and standard outlets to save energy. Installing all-in-one USB + 120V standard outlets in a travel trailer requires the energy to be converted and then inverted back, wasting precious power that we really can’t afford in a camper.
*Unless, you make a bonehead move like we (I) did and buy a couple of totally awesome, but totally 120V accent lights… Check before running your wires: If your light has 3 wires (a hot, a neutral and a ground) it is a 120V light and should have black, white and green wires run to it. If it has only 1 (a hot, that’s grounded through the mounting hardware), or 2 (a hot and a neutral), then it’s 12V and should have red and black wires run to it.
A breakdown of all the components
Converter vs. Converter/Charger vs. Inverter
Converters and inverters perform mirror functions of each other and both are necessary for what we chose to do in The Cameo.
Converters convert 120V AC power to 12V DC power. You need a converter to get city/shore power (from the campsite, your house, a generator) into your battery bank. (Our converter/charger is the big yellow box in the upper left.)
Converter/chargers convert 120V to 12V just like a plain ol’ converter, but they also continuously charge the camper’s battery which allows you to boondock (a fancy term that means you can camp and run your stuff without being plugged in, allowing more freedom to stop wherever you want) without a power source so you can really go off-grid, if only temporarily.
Inverters invert 12V DC power to 120V AC power and passes it along to the connected equipment. You need an inverter to run your household AC electronics from the battery. In the case of a power outage, the inverter will automatically switch to battery power to provide power to the connected equipment. (The big blue box in the upper right is our inverter.)
What type of battery did you use?
A really heavy one – 128.97 pounds to be exact. (Which is why before we began electrical we had to rebuild the wheel well frame to support the beast.)
More specifically, after researching and contemplating if we wanted a single, double or multiple batteries, we opted to go with a single 12V deep cycle marine battery. It’s an Absorbent Glass Mat (AGM) battery, which though more expensive, it’s significantly less maintenance and safer than a wet cell battery (which can explode if in confined spaces… yeah, no), and safer than the “no maintenance” version of the wet cell battery (called gel cell) which also need ventilation. AGM batteries also charge faster than the other kinds and have a longer lifespan.
What’s a bus bar?
Negative bus bar – you can tell it’s the negative since it has black wires hooked up to it.
A bus bar is basically just a line of terminals that allow us to bring power in through a single source and pushes it out to multiple items all from one source.
What’s a fuse block?
The fuse block is the clear rectangular box on the right {the one with the (+) on top and (-) on bottom}.
Similar to a bus bar, fuse blocks allow one source of power to come in and multiple sources to go out, all with the added safety layer of going through fuses. Sort of like a breaker panel for the camper, if we ever have an issue with a particular 12V item and overload it, the corresponding fuse will pop and protect the rest of the system from damage.
Did you go with 30 Amp or 50 Amp inlet for shore power?
30 Amp – We’re a pretty small rig and since we don’t have one of those multi-room, 2-air conditioner RVs, a 30 Amp hookup should be more than enough to power all of our appliances. (It’s the port on the left.)
Yeah, yeah, but how does it all go together to power my stuff?
How our camper’s electrical system works
Gimme the cliff’s notes version:
Power comes in from the “shore”.
It runs to the battery, charging it, which then runs to the inverter, powering it.
The inverter is responsible for powering the 120V AC electrical.
Power also runs from the 12V battery to the 12V DC electrical.
I need more detail:
Power comes in from the “shore” and into the converter. For this, (after we tested to make sure it worked by plugging it into the house) we cut off the electrical plug from our converter and hard wired it into the back of our exterior shore power port.
From the converter, a positive (red) 8AWG cable goes to a breaker switch for safety, then into the positive bus bar. A negative (black) 8AWG cable also runs from the converter directly to the negative bus bar.
From the positive bus bar, a second 8AWG positive cable goes through a second breaker switch and then to the positive end of the fuse block. A third positive (2AWG) cable runs from the positive bus bar to the positive side of the inverter. A fourth positive (2AWG) cable goes through an emergency kill switch and to the positive side of the 12V battery. The positive side of the battery has a terminal fuse added to it.
That’s it for our positive “hot” cables (except of course for the small ones that are running each of your appliances, lights, etc.).
We already have the negative bus bar connected to the converter. In addition, a negative 2AWG cable runs to the negative side of the 12V battery. An additional 2AWG negative cable runs from the negative bus bar to the negative side of the inverter, and a negative 2AWG cable runs from the negative bus bar to the negative side of the fuse block.
All of the positive and negative 12AWG wires for your 12V appliances/lights/etc. attach to the fuse block.
All of the positive, negative and ground 12AWG wires for your 120V appliances/lights/etc. should be hard wired into a grounded electrical plug and plugged into the inverter directly (as if you were plugging it in at your house).
And that’s it. Assuming you’ve got your camper grounded, which brings us to…
You can see we chopped off the 120V plug from the end of our converter/charger, pushed it through a hole we cut in the side of the camper and hard wired it into the back of our 30 Amp shore power inlet using the white, black and green wires found inside the thick power cord.
Why being grounded is a really, really good and totally necessary thing
We didn’t do this until later, basically because we didn’t realize we weren’t already I guess, I don’t know. Bottom line is DO THIS FIRST and save yourself so much headache and time. In fact, even though we did this last, I’m going to break this part out into its own separate post just about grounding because it really is that important.
Not having a proper ground causes all sorts of problems and irritations and basically can and will waste a bunch of your time. In our case, we had to ground to both the chassis (camper trailer) and bare aluminum walls. Emphasis on making sure you’re grounding to bare aluminum and clean (read: not rusted) chassis. If you don’t, you’re just asking for problems. Just trust us on this.
Grounding materials:
*Shopping list links in section below
8AWG 15’ red and black cable (we only bought 1 – we were able to use what was left from our cabinet list)
Machine screw + matching hex nut – (we had some laying around from who knows when. If you wanted to mount from the outside you could use a self-tapping metal screw, but we wanted to keep the camper exterior as clean as possible and opted to mount inside-out)
Anti-Oxidant Joint Compound – improves the conductivity of aluminum electrical connections
Grinder/Dremel for cleaning your metal wall and chassis
Drill + bits to match your screw choice
I never thought we’d be glad a mouse chewed a hole through our plastic wheel well cover. But here we are. We’re nothing if not resourceful, I guess. This little hole, along with a clip, allowed us to stealthily ground our camper. After we used the Dremel and grinder to clean our mounting areas inside the aluminum wall and on the chassis, we pre-drilled a small hole in the aluminum wall in preparation for our machine screw. We ran the 8AWG wire from our negative bus bar down between the stud and aluminum wall, down through the mouse hole, and under the camper to the bottom of the wall. We added the heat shrink ring connectors on both ends after we threaded the wire (because it would’ve been too tight to thread behind the studs with the fitting already on the end). As we threaded our ring connectors onto our mounting screws, we used the anti-oxidant joint compound per the directions on the tube to increase our ground’s conductivity.
We then made a “jumper” using the same 8AWG wire connecting the camper wall to the chassis following the same steps above. After tightening down the hex nut on the outside wall, we cut off the extra machine screw so it was flush to the hex nut, and plan on painting over it to blend it into the screws already around our wheel wells.
We confirmed we were grounded properly when our 1-wire porch light (that grounds through the camper) turned on.
Our predicted power consumption
It really helped us make decisions on what we needed to buy by breaking down our estimated power loads into the below table format. Not super sexy, but highly functional in the planning stages. It also helped us not have to check all over the internet for each appliance’s specs multiple times. We used a conversion tool for finding out Watts to Amps to Volts and every combination needed.
Our electrical cabinet shopping list
Brace yourselves. This list ain’t cheap, but we’ve added safety measures we haven’t seen on a lot of campers and beefed up some areas in preparation to expand down the road should we need/want to.
Gulp:
250 Amp terminal fuse – (sits on top of the positive side of the battery)
Terminal mount fuse block – (what your fuse sits in on top of the battery)
12AWG colored + length as needed to run your lights/appliances/etc. (we used red, black, green and white for our AC and DC wiring)
Heat gun – we borrowed from a friend, and made really quick work connecting the heat shrinks.
Strippers – we already had some, but you’ll need to be able to cut and strip 12AWG, 10AWG, 8AWG and 2AWG wires/cables – (we were able to get away with just slowly clipping the protective casing off of the 2AWG instead of buying a separate set of mega strippers)
Hammer lug crimper – we were able to borrow one from a friend which worked really well. You could also buy a hydraulic style crimper (for 2AWG cables) but they’re expensive (about $60) for us to use it just this once.
Room to grow
We don’t plan to install solar panels right now, but with this system we can always add them (and plan to) down the road without having to redo the whole system.
Additional electrical resources
Here are some of the most helpful camper electrical resources we referenced when building our system:
HUGE thanks to Far Out Ride – hands down the most comprehensive and helpful source we found. We purchased their $30 electrical plan which was invaluable. We highly recommend their planning tool and most everything we learned came from these saints.
Roamlab – Excellent breakdown, specifically on different types of batteries, and one of the big reasons we chose an AGM battery.
So, did we scramble your brain?
I hope not, but if it’s feeling like mush right now – trust me, we’ve definitely been there — and if you’ve learned nothing else from this post, please take away that you need a good ground. That is, if you want any of your lights/electrical to actually work.
For all you visual/photo lovers:
We’ll be sharing an attractive lights post at some point to balance out this not very pretty, nitty gritty how-to-wire-your-travel-trailer-from-scratch post.
For anyone wiring a camper from scratch:
You got this.
