ON-OFF. How hard can switches be, right...? Well, I remember being completely baffled when I wired my first switch panel. Unfortunately campervan switch panel wiring can be a little tricky to understand at first! 😢 So in this guide I will seek to enlighten you in the ways of the 12v rocker switch! We will look at simple 2 pin switches, all the way up to 5 pin gang rocker switch panels with USB chargers, and battery monitors. We will examine some 12v switch panel wiring diagrams, as well as how to wire a rocker switch to a fuse box. 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 campervan switch panel wiring!
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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 switch panel wiring is included in the diagram 🙂 - it gets sent out to you straight away).
Supplies list 🛒
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 | For connecting wires |
 | For splicing one wire into another |
 | For protecting wire connections after crimping |
 | For compressing heat shrinks on crimp connections |
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 | Roof lights |
 | For crimping wires |
 | For stripping wires |
What is a Switch?
A switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit. On command it can break a circuit, thus turning an appliance off.
The most common types of switches in campervans are:
Rocker switch (left)
Isolator switch (middle)
Inline circuit breakers - can also be used as switches (Right)
Isolator switches are large and bulky; they are normally used for the leisure batteries or the inverter.
Inline circuit breakers are used to protect devices like your solar charge controller. You can learn all about fuses and breakers in this guide.
In this guide we will focus on rocker switches, as these are what we commonly used to control our 12v DC appliances. They can be installed individually or in a group (campervan switch panel wiring). They are very commonly used in vehicles. Later in the article, we will look at how to wire a rocker switch to a fuse box.
12v Rocker Switch Positions: Poles and Throws
There are four types of rocker switch:
Single Pole, Single Throw (SPST)
Single Pole, Double Throw (SPDT)
Double Pole, Single Throw (DPST)
Double Pole, Double Throw DPDT)
Let's examine the terminology:
Poles
Poles refer to the number of separate circuits the switch controls. If a rocker controls just one circuit, it is a single-pole rocker switch. If it controls two separate circuits, it is a double pole switch.
Throws
Throws refer to the number of ON positions the switch can move between. A simple on-off switch, is known as a single throw switch. If it has two ON positions - eg. OFF, low, and high - it is a double-throw switch.
Rocker switch Poles and Throws Examples
Single Pole Single Throw - SPST
A rocker switch that just controls a simple LED light (ON-OFF) is SPST.
Single Pole Double Throw - SPDT
A rocker switch that controls an LED light with a high and low brightness (OFF-LOW-HIGH) is SPDT.
Double Pole Single Throw - DPST
A rocker switch that controls two simple LED lights (one turns ON when the other is OFF and vice versa) is DPST.
Double Pole Double Throw - DPDT
A rocker switch that controls two LED lights (one turns ON when the other is OFF) with a high and low brightness (OFF-LOW-HIGH) is DPDT.
12v Rocker switch terminals/pins
A 12v rocker switch can have between two and eight metal terminals/pins on the underside into which we wire.
Note: Rocker switches with a lamp
When a rocker switch has a built-in LED lamp (to indicate whether it is on or not), we generally add one extra pin (ground/negative) for the light itself. Rocker switches with lamps are very common
How to wire a 2 pin 12v rocker switch
The 2 pin rocker switch (SPST) is the simplest rocker switch to wire up. As you might remember from physics class in school, this switch simply goes between the battery source and the appliance.
In a van conversion, we must fuse our appliances to protect them; so we install a 12V fuse box to help with that. Learn about fuse boxes and fuse sizing.
After the fuse, we will add the switch to the circuit.
How to attach a wire to a rocker switch
The pins on the underside of the rocker are male blade terminals. We can connect a wire to these pins using a female 'quick disconnect' crimp connectors. Learn about crimp connecting.
How to wire a 3 pin 12v rocker switch
3 pin rocker switches are very common in campervans. They have 3 pins because they have a small LED lamp which needs ground/negative.
One of the three pins on the rocker switch should have a brassy colour - this is the negative of the LED lamp. We can wire this pin to the negative bus bar of the Fuse box.
How to wire a panel of 3 pin rocker switches
When we have many 12v rocker switches, we will typically bunch them together in a switch panel. Campervan switch panel wiring can be a little tricky, so let's dive in and have a look at how to deal with them. A 12v switch panel wiring diagram is included along with an explanation of how to wire a rocker switch to a fuse box.
Scenario 1:
One of the most common switch panels is the one shown in the photo below. It has the Positive IN and LED Negative OUT already wired up and ready for connection to the fuse box. All that is left to do is wire the appliance into the middle pin.
However, there is a problem with the out-of-the-box wiring of this panel... Notice that all the Positive INs are daisy chained together. Where does the fuse go? We have two options:
Option 1: We can insert an inline fuse on the wire running to the appliance (from the middle pin)
Option 2: Rewire all the daisy-chained Positive INs to run to the 12v fuse box (ie. remove the daisy chains). Each switch will have an individual blade fuse in the fuse box. The negatives can stay daisy chained (negative is just common ground in DC systems).
12v Switch panel wiring diagram
The above diagram show you how to wire a rocker switch to a fuse box. Wiring a rocker switch panel to a fuse box is my personal preference as a fuse box is a very neat way to keep all your fuses in one place. Not only this, but it will also protect more of your system; If we use inline fuses (option 1), the wire from the power source to the switch will not be protected from surge (fire hazard).
How to wire a panel of 3 pin 12v rocker switches with USB chargers
Another very popular type of rocker switch panel is the one shown in the one shown in the image below; it has usb chargers, a cigarette lighter, and a battery monitor.
The wiring for this type of panel will be much the same as a standard 3 pin rocker switch panel.
We can choose to use the inline fuse method (we normally get the blade fuse holders already wired up - like the photo shows below).
Or we can choose to wire everything back to our 12v fuse box, in which case we will need to rewire all the daisy-chained Positive INs to run to the 12v fuse box (ie. remove the daisy chains), and we can also remove the wires with the inline fuses.
With this type of switch panel we run into the same problem as before with the out-of-the-box wiring of this panel... Notice that all the Positive INs are daisy chained together. The USB socket, cigarette lights, and battery monitor aren't even fused!
So, just like with the switches, we should remove the daisy chained positives and rewire each of these appliances back to the fuse box individually.
How to wire a 5 pin gang rocker switch panel
We're getting into more tricky territory now. Campervan switch panel wiring ramps up in complexity a bit. Some people buy these types of switch panels and then nearly lose their minds trying to wire them. Each rocker switch has FIVE pins on the back. Each switch has a dim backlight that always remains ON, it also has a main LED lamp that turns on when the switch is turned ON.
Why the heck are there five pins?
Positive IN for LED backlights (always on)
Negative OUT for LED backlights (always on)
Positive IN for appliance
Positive OUT for appliance
Negative OUT for LED lamp (Turn ON when switched)
However, once again the lovely people who supply the switch panels have daisy-chained the positive appliance INs together for us. This is fine(ish) if we are going to use inline fuses on the way to our appliances. However, if we want to fuse everything from our 12v fuse box, once again we will need to remove the daisy-chains and wire each switch individually.
Here is an excellent video from a guy who wires up (and even customizes) a 5 pin gang rocker switch panel. He shows excellently how to wire a rocker switch to a fuse box.
Conclusion
And there we have it! Everything you need to know (and probably more) about 12v campervan switch panel wiring! I found these switch panels confusing when I first came across them, so I hope you found this article useful! Don't forget to subscribe to The Van Conversion Newsletter for everything you need to get started with your own van conversion (I'll send you a free wiring diagram when you sign up which includes the switch panel wiring diagram).
Be sure to check out the rest of the Electrics Guides. Related articles include: campervan fuses and breakers, campervan wiring, campervan solar panels.
If you're converting a van but unsure of how to do it, you could also check out the Van Conversion Course on Udemy. In the course, you'll learn directly from me how to convert a van into your dream home - no prior experience needed!
Until next time,
Shane ✌️