Before you can light up the first LED in your camper, you need a functioning and safe electrical circuit. In addition to the consumer, a 12 volt battery, and the cables, you will also need a few other parts, which we will now bring to the correct position in the circuit step by step.
12V from the battery to the consumers, we installed that
- Fuse holder car
- neutral terminal
- main switch
- Car flat fuses
- Switch for cars
The first 12V wiring diagram for the camper electrics
While the professionals usually install simple work without a circuit diagram (almost “out of their heads”), a circuit diagram was essential for us. Important information gets lost too quickly during all the new knowledge. When working with electronics, extreme concentration is always required. There is a lot to consider, and the small things often ensure the safe functioning of your camper electronics.
How the electricity gets to the consumer
First, the question arises about how the electricity gets to your devices, the consumers. Basically, and to put it in a very simplified way, the current always flows in one direction. From the onboard battery via the positive line (red cable) to the consumer and back to the battery via the negative line (black cable). Zack, the cycle is complete. The negative lead is also often referred to as ground leads in vehicles. Because the battery (with the negative cable) is connected to the body, as an alternative to a negative cable, one could also use the body’s electrical conductivity and connect each consumer to the body from the negative pole. The current would then flow back to the battery from the consumer via the body.
Install 12V fuses
Every power circuit, which means every consumer, must be protected against cable fires or similar painters by installing a suitable fuse. For this, you need a fuse holder to install the fuses for the respective circuits. For the 12V electrical system, it is advisable to use so-called flat car fuses. These can simply be plugged into the fuse holder. If a fuse blows, you can easily replace it. For the fuse to do what is expected of it in the event of a fault, it is important to choose the strength of the fuse so that it reliably protects against damage to the consumer or the cable. If the strength of the fuse selected is too high, it will not trip in the event of a fault. If the fuse is set too low, it can react to the simple use of the consumer, i.e., it can burn out as soon as it is switched on.
The installation of switches
All 12V consumers not operated via a cigarette lighter or a 12V socket need a switch so they are not permanently in operation. This usually affects the LEDs and the water pump. The principle of a switch is very simple. It interrupts the circuit or connects it, depending on the toggle position of the switch. Installation is just as easy. At the point where the toggle switch is later to be placed in your car, you have to cut through the positive line. The cable is now stripped, and the appropriate cable lugs are attached. You can then simply slide these onto the connections of the toggle switch. Don’t worry; you can’t swap anything here.
Install a three-terminal toggle switch in the camper
Some car switches have two or three connection points on the back. These switches are usually equipped with a small LED, which lights up as soon as the consumer is switched on. We find this function unnecessary, but unfortunately, we didn’t pay close attention when shopping and buying such switches.
Connecting these switches is a little more complicated because you must pay attention to the correct wiring. On the back, there are usually two gold and silver connectors. With the two connectors of the same color, everything stays the same. The two cable ends of the positive line can be connected here. On the other hand, the silver connection part is the negative connection of the LED in the switch. Accordingly, a negative line must be attached here, which is then attached to the neutral conductor terminal or the ground. In our case, we simply left this third connection free. The toggle switch works without the LED, just like we wanted.
Series vs parallel battery, which circuit for the camper electrics? So far, in this article, we have created a separate circuit from the battery for all consumers and installed them in parallel. Connecting your consumers in parallel has some advantages, so we used them for all consumers in the camper.
Sometimes, however, it makes sense to let several consumers or voltage sources run on a common power circuit. For example, we use this technology for the solar cells. Then the solar cells are lined up one after the other, and we speak of a series connection. This circuit has the advantage for our solar cells: we can work with higher voltages. However, if one of our solar cells fails, the entire power circuit and the other cells also fail. In this case, troubleshooting is considerably more complex than if we had connected the solar cells in parallel. The same applies, of course, to consumers that are connected in series.
Operate several consumers via one switch
You should always connect your LEDs in parallel, as wiring them in series can reduce the brightness of the individual LEDs. Nevertheless, it often makes sense to be able to use a common switch for several lamps. This is also very easy. You only need WAGO terminals with three or more inputs, depending on how many parallel circuits you want to bring together here. For example, three conductor inputs are required for two lamps, four for three lamps, and so on. By connecting to the WAGO clamp, you can combine several circuits connected in parallel on one cable and install a switch there. Several lamps can already be operated via a switch.
Install the main switch
You can also use the same principle when installing a main switch. The aim of this should be to be able to quickly disconnect all circuits from the battery if necessary. To do this, you simply install a (usually large, red) switch between the battery and the fuse holder.
Connection to the battery
The last step of the 12V installation is always the connection to the deep cycle battery. Now it’s getting exciting. Because now you can see whether you have wired everything correctly. This was a really big step that cost us a lot of effort. Ultimately, however, everything is half as wild. It is recommended to first attach the cables to the designated screws on the pole terminals. These are then placed on the battery. Attention usually sparks something. Don’t let that stop you; just quickly press the clamps into place. As soon as these are firmly in place, the spook is over.