Wiring is EVERYWHERE. 🔌 Inside the phone or laptop you're using; in the lights above your head; even in your grandmother's pacemaker! Yet, so few of us know anything about them... In this guide you will learn everything you could ever want to know about campervan wiring. What are the different types of wires? How do you size wires? How do you connect wires together? How do you crimp, solder, and heat shrink? This information-packed guide will give you everything you need to know about how to wire up your campervan electrics. I'm Shane, I've been teaching people to convert campervans for many years, I'm the author of The Van Conversion Newsletter, the van conversion instructor at Udemy, and the proud owner of a beautiful self-build campervan called Beans. So let's jump in and have a look at wires for campervans!
This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc.) we will receive a commission fee. The price you pay remains the same, affiliate link or not. By using these links, you are helping me to continue writing free educational content!
Index
Note: Before we hop in, you will definitely want to grab yourself a wiring diagram which you can get for free by signing up to The Van Conversion Newsletter (the campervan wiring for an entire van conversion is included in the diagram 🙂 - wiring diagram gets sent out to you straight away).
Supplies list 🛒
| Wire Connectors |
|---|---|
 | For connecting cable to ring terminals |
 | For protecting wires & connectors after crimping |
 | For splicing one wire into the middle of another (eg. wiring puck lights) |
 | For connecting wires to 12v appliances |
 | For splicing wires |
 | For connecting wires together |
 | Screw terminal connector block For connecting wires together (eg. wiring water pump) |
 | Old way of connecting wires |
 | For connecting wires to connector blocks or appliances (eg. Solar charge controller) |
 | Heat shrink & crimp all in one! |
 | Essential for any electrician. For connecting / protecting / differentiating wires. |
 |
| Tools |
|---|---|
 | |
 | For testing / checking your campervan electrical system |
 | Cutters, Stripper, and Crimper all in one! For small wires |
 | Large crimping tool and cable cutters For cutting and crimping large cables |
 | For crimping wires |
 | For stripping wires for crimping |
 | For compressing heat shrinks on crimp connections |
 |
Campervan Wiring: Sizing, Material, and Types
Electricity is the flow of electrons. When electrons are "lost" from an atom, the free movement of these electrons constitutes an electric current. Electricity travels through wires - a metal conductor that is sheather by an insulator (usually rubber or plastic). A conductor is a material that allows electricity to flow through it. The insulator blocks electrical force from passing through it.
What types of metal are wires made from?
Wires are typically made using the following metals:
Copper
Aluminium
Gold
Silver
Tungsten
Copper is by far the most common metal used. It is highly conductive, bendy, thermal resistant (safer), and a lot less expensive than most of the other metals.
Aluminium is the second most common metal used in campervan wiring. It is very light weight, long-lived, an extremely good conductor, and corrosion-resistant.
Aluminum has 61 percent of the conductivity of copper, but is only 30 percent of the weight of it. Consequently, aluminum offers a lower cost per amp and provides up to 48 percent mass reduction over copper. Aluminium is becoming increasingly popular and I would recommend it. However, if you use the campervan a lot by the sea, you should go for copper as aluminium corrodes easily.
What is tinned cable?
Sometimes copper wire will be tinned, whereby the wire is coated with a thin film of tin to protect against corrosion. This gives the wire a silvery appearance as opposed to the usual brass/copper color. Tinned cable is useful if you are using the campervan by the sea. Solar cable should be tinned as being on top of the campervan, it is constantly exposed to the elements.
What is the difference between solid wire vs stranded wire?
Solid wires consist of a solid core, whereas stranded wire consists of several thinner wires twisted into a bundle.
Stranded (concentric) wire has many layers of wires, gently twisted into a helix shape. Each layer has six more wires than the previous layer (6^n).
Stranded wire is more flexible and more resilient to damage and being bounced about.
Solid wire is a better conductor, but a lot less flexible.
For campervans (and in all vehicles), we should use stranded wire.
What are the different types of wire insulators?
Three types of wire insulators are available: plastic, rubber, and Fluoropolymer.
Plastic:
Plastic insulators have a number of useful characteristics ideal for wire insulation; including ductility, electrical resistance, UV resistance, and fire resistance. PVC is the most commonly used and is quite cheap.
Rubber:
Rubber insulators are more flexible than plastic, especially at lower temperatures. They are resistant to a broad range of temperatures, UV radiation, and wear.
Fluoropolymer:
Fluoropolymers are polymers that are especially resistant to bases, acids, and solvents. These are specialized wire insulators
For campervans, people will usually use plastic (PVC) insulated wires.
Note: All wire insulation has a temperature rating printed on the outside; the maximum safe operating temperature (eg. 200°C).
How to calculate diameter for your campervan wiring
To calculate the size (diameter) of wire needed in a system we need two variables:
The length of the wire (distance to the appliance AND back)
The amps the wire will be carrying (ie. the amp rating of the appliance)
Is the circuit critical or non-critical? (voltage drop discussed below)
When we have these two pieces of information we can plug the variables into the wire size calculator over at http://circuitwizard.bluesea.com/ or consult the BlueSea diagram below (the formula for wire sizing is quite complex, so use these tools instead!)
Note: AWG (American Wire Gauge) and mm² (cross sectional area) are the units of measurement used to describe wire size. AWG is used in North America, mm² is used everywhere else. There is a third unit of measurement called CMA (Circular Mil Area) which is very precise, and technically better when dealing with stranded wire. However for most people, this level of precision will not be needed.
What is voltage drop and why is it important?
Voltage drop occurs when the voltage at the end of a section of cable is lower than at the beginning. Voltage drop normally occurs when there is resistance in current flow usually due to cables, contacts or connectors.
We can only allow a 3% voltage drop on sensitive/critical circuits, whereas we can allow up to a 10% voltage drop on non-critical appliances (eg. LED lights).
Here is the wire sizing I used in my conversion (you can get a free campervan wiring diagram of my system by signing up to The Van Conversion Newsletter):
12V appliances: 14AWG
Solar panels to solar charge controller to batteries: 8AWG
Batteries to inverter: 2AWG
Batteries: 0AWG
Related guide: Wire sizing, fuses, and general electrical concepts
Bonus content: If you're interested, here's a cheesy video showing you how wires are made!
How to cut and strip wires
Knowing how to cut and strip wires is as important to an electrician (and van converter) as knowing how to use a knife is to a chef. It's the basics, upon which all else is built.
How to cut wire
Here are the three types of wire cutting tools that are typically used to cut wire:
1. Small wires (22-10AWG) can be cut using a wire stripping multi tool, or simple pliers. A multi tool cuts, strips, and crimps smaller wires. I would definitely recommend getting one!
2. Medium-sized wires are commonly cut using a cutting pliers (Knipex).
3. Large wires are cut using large wire cutters, which give extra leverage.
How to strip a wire
Stripping a wire, simply means cutting back the rubber insulator around the wire
It is important that we strip the wire correctly, meaning not nicking, cutting, or breaking wire strands!
If we nick or cut strands, it results in decreased electrical and mechanical strength. If we have an uneven or tapered strip, it will result in a poor crimp connection (for connecting to another wire), it will also give less effective insulation support
To strip a wire, we use a wire stripping tool.
Small wires (22-10AWG) can stripped using a wire stripping multi tool.
Large wires are typically stripped manually using a Stanley blade.
To strip a wire using a Stanley blade, hold the wire with your thumb and trace around the rubber with the knife.