Running wires is the process of creating electric ‘highways’ (or well, tunnels, is more accurate) of wires to get the electricity from your batteries to where you need it the most in your van.
We do this by running wires through tubes (known as conduit) through the gaps in the vans metal framework.
It’s done early on, because to try and retro-fit electrical appliances and forcing wires behind insulation and walls is really hard.
To do this, we are going to need to make sure our layout design is sorted, and we know where we want things like batteries, plug sockets, the fridge and lighting to live.
This article will look briefly at wires (because we have more information on using the power and wires here), and then how to run the wires through conduit now, when it’s nice and easy to do.
Wires
Some context. A wire is a flexible metal strand that conducts electrical energy. The flow of that electrical energy, also known as current, can be dangerous or even deadly if not handled properly. That’s why wires are covered by a plastic sheath to protect them from damage and prevent conductive elements from getting an unwanted fix of electricity. We need wires to take electricity from the battery to the things we need to power.
When it comes to wiring a campervan, sizing wires correctly, using the right type of cable, and planning efficient cable runs are crucial for a successful installation.
Types of Wires
Different types of electrical cables have different purposes, so choosing the right one for your needs is crucial. In a nutshell:
Opt for Multi-Stranded Cable, made up of several tiny copper cores, which is more flexible and less likely to break.
Solid Core Cable, made up of one solid copper wire per conductor, is a no-go for van conversions as it’s not flexible and can snap when over-flexed.
It is recommended to use oxygen-free copper wire to better withstand vibrations caused by a van’s drive.
Other types of cable that will work include twin core, tri-core, and thin-wall cables.
Finally, pay attention to the number of insulated wires in the outer sheath, which determines the type of cable, and choose cables certified for automotive purposes.
Wire sizing in a campervan
When we talk about wire size, we are talking about the cable thickness (or cross-section diameter), not the length. Choosing the correct wire size is a fundamental aspect of a successful wiring installation.
There are three factors to consider when selecting the correct wire size: current, circuit length, and campervan wiring regulations. To determine the correct wire size, you need to calculate the current rating and the length of the longest circuit.
The wire needs to be able to handle the amount of current passing through it without getting too hot or burning; that’s how fires can start.
Longer circuits, and more load, require larger cables.
The standards of wire size and current load are defined by mm metric scale in the UK and Europe, and AWG size in the US. We need to be smart and choose the right wire size.
Connecting wires
The reason soldered connections are not commonly used in campervans is because soldering may not provide a robust mechanical connection. Solder joints will become brittle and fail. So, you’ll want to avoid soldering whenever possible.
Besides the above, soldering can be messy, time-consuming, and difficult to get right, especially in a cramped space like a campervan. If not done properly it may not provide a robust enough connection and even if it is done right, the movement of the vehicle may also weaken the soldered connection.
Good news for us, we don’t need to buy irons, solder, or get involved with that. What do we do instead? Instead, use a crimp tool and cable lugs to make your connections.
For this we will need an array of metal connectors/ cable lugs. These small metal sleeves are crimped onto the end of a wire and help to ensure the best possible conductivity.
They’re particularly useful when connecting wires inside terminal blocks, which are a great way to merge or divert cables. When selecting a terminal block, be sure to choose one that is recommended for the size of cable you’re using. This will ensure that your connections are secure.
Crimping, cable lugs and cable terminals is a faster, cleaner, and the most reliable method of connecting up wires.
Conduit
Conduit is basically a plastic tube that when installed acts as an easy route to push your wires through, and provides some additional support and security for the wires when you are out on the road.
How to run wires in a campervan
Pre-flight checks
Before you start running cables, it’s essential to do your pre-flight checks. Check your instruction manuals for items you want to wire, double check your electrical design, triple check your maths, and make sure you have everything you need to hand.
Display where everything will go
It’s time to determine the placement of all electrical equipment, such as your appliances, sockets, lighting, and power sources, and stick post-its on your van where they will be. This will make it easier for you to visualise where everything will go and plan your cable runs accordingly. You could use post it notes, or write on the walls.
Run conduit along the planned cable runs
Next, run conduit, which are basically tubes that your wires can sit in and be protected, along the planned cable runs. The conduits go through the walls and can split off from main lines into smaller ones, depending on where your electrical needs are.
Think of the conduit as a rabbit run for your wires. To make the next stage easy, pick the right diameter conduit for the amount and size of wires you will be running through.
Be sure to secure the conduit with tape or cable ties to prevent it from moving around. Some people choose to run their wires outside the van (through the floor), which is something we don’t do.
Run the cables
Once you have your conduit in place, it’s time to run your cables. Insert the cables into the conduit. You can push them in from one side. Warning, this can get a bit tricky and you might want to use a small cable probe, or if it’s really bad even reconfigure the pipe layout. Leave plenty of extra length for contingency. Remember that each outlet will require a positive and negative wire, unless you’re using the chassis for negative.
Tips
Accessibility First!
Nobody likes taking apart half of their campervan just to fix a broken cable or poorly done crimp. That’s why you should make all splices, cables, and junctions accessible in case of worst-case scenarios. Future proof by doing a good job, and don’t make things harder for yourself later on.
Secure Everything!
On the road, loose electrical cables are a no-go. So, make sure everything is tightly secured with zip ties. This will help prevent the cables from banging against surfaces when you’re on the move.
Study Before You Start Wiring
Careful planning and research are essential when it comes to wiring a campervan. Think about everything you want to include in your electrical system, and create a clear diagram or plan. This will save you time and headache in the long run.
Ask an Expert
Are you not sure what to do? Get informed, ask the internet for advice, or better yet, consult with an expert. The electricals are not something you want to play guessing games with. It’s always better to be safe than sorry.
Insulate, Insulate, Insulate
Duct tape might fix anything, but insulating tapes will protect your wires. Cover wires exiting terminals, join multiple wires together, and reinforce and protect any junction with plenty of insulating tapes.
When In Doubt, Go Big
It’s always recommended to oversize the cable for the total load. Better to have too large a cable than too small. This will make sure that your electrical system is equipped to handle any potential loads.
Throw in a Few Spare Wires
Futureproof your campervan by adding a few extra wires. You never know what additions or changes you might want to make in the future.
Label Your Wiring
Use labels to identify cables and keep track of which ones go where. This will save you time and hassle when you’re troubleshooting or making changes. Be square, label your wiring.
Van Chassis
Avoid using the van chassis as a negative wire, if you can help it. Instead, make sure each electrical outlet receives a positive and negative cable. If you are using the chassis as a negative, try to connect it up as close to the battery as possible.
Materials needed:
- Corrugated pipes and sheaths are two almost equivalent products with pros and cons. Corrugated pipes are cheap, easy to slide into gutters, but can be cut/ damaged easily.
- Sheath conduits last longer, support vibration, and are extremely flexible. Some people run sheath conduit under the van (although we don’t advise this)
- Garden hose pipe
- Duct tape
- Wires (likely sizing)
- Cable ties
- Post it notes
- Electrical Tape
What we did
Our van came with a bunch of 12v accessories already wired in, so we got lucky with some components like lighting and sockets. However, the wiring didn’t look like it was don’t done professionally, so we took the decision to re-do the 12v wires.
Because we were undertaking this on a van with walls, we were forced to get a bit creative on how we ran the wires. The end result was that we took one big cable through the roof, with a lot of difficulty, to a fuse box with all of the 12v fittings towards the rear of the van.
The cabling to appliances at the front of the van was run along the inside of the cabinetry, from an additional fuse box at the front of the van. We used pillars behind the cab to hide the wiring from the solar panel down.