Installation Materials

Suitable cables, secure connections and protected cable routes form the foundation of your camper van’s electrical system. Here you will find installation materials for wiring your motorhome – from automotive cables and cable lugs to plug connectors and cable seals. The key factors are the required current capacity, matching connection sizes and the conditions at the installation location.

Which installation materials do you need for your conversion?

Choose your installation materials to suit your wiring diagram and the devices you want to connect. Under “Cables & Wires”, you will find cables for your installation, while “Cable Routing” covers materials for routing cables and passing them through surfaces. “Plug connectors” provide removable connections, and “Cable Lugs” contains suitable terminals for your cable ends.

Always plan the complete connection: from the terminal on the first device, through the cable and its circuit protection, to the terminal at the other end. A correctly sized cable is of little use if a connector or terminal cannot handle the required current.

Choosing cables: match the cable type and cross-section to the application

A cable must be suitable for its intended use. In a vehicle, vibration, temperature and mechanical stress matter alongside the electrical load. Flexible automotive cables serve different purposes from cables intended for a 230 V installation or solar cables permanently installed outdoors. Start by choosing the appropriate cable type, then determine the required conductor cross-section.

The cable cross-section in mm² describes the cross-sectional area of the electrical conductor. It is not the same as the outer diameter of the insulated cable. When choosing a cable lug, you need the conductor cross-section; for a cable seal, you need the cable’s actual outer diameter.

Current, cable length, permissible voltage drop and installation conditions all affect cable sizing. A long cable may need a larger cross-section than a short cable carrying the same current. Bundling cables and high ambient temperatures also affect their permissible current capacity.

Allowing for cable length and voltage drop

Particularly in 12 V systems, voltage drop along the wiring can have a noticeable effect: the voltage reaching the appliance is lower than the voltage at the battery. This can reduce performance or cause a device to shut down due to low voltage.

Include the complete current path in your calculation. For a connection with dedicated positive and negative cables, this means their combined length. When using tables or calculators, check whether they require the one-way distance or the total circuit length.

Measure the actual cable routes you plan to use, allowing for bends and a little extra length for making connections. Unnecessarily long cables, however, increase resistance and take up more space. Base your choice on your devices’ connection requirements together with a calculation for your specific installation.

Cable lugs: match the conductor cross-section and terminal size

Two dimensions need to match when choosing a tubular cable lug: the barrel size for the conductor and the hole size for the terminal stud. A lug marked “25 mm² M8”, for example, is designed for a suitable 25 mm² conductor and an M8 terminal stud.

Also check that the shape and dimensions suit the connection. The lug must sit flat against the contact surface, with enough room for the cable exit, bend radius and any protective cover. For blade connections, the contact dimensions and matching connector also matter.

A reliable crimp requires a compatible cable, terminal and crimping tool. Choose the tool and crimp profile to suit the specific connector. Suitable heat-shrink tubing insulates the connection area, but it does not replace a correct crimp or proper cable strain relief.

Plug connectors: suitable for the load and the environment

Plug connectors are useful when you want to disconnect components for maintenance, removal or portable use. Alongside the number of poles, compare the rated voltage, current capacity and supported conductor cross-section. The housing and contacts must be designed to work together.

Also consider where the connection will be located. A protected interior location has different requirements from one exposed to moisture or splashing water. Check the conditions under which a stated ingress protection rating applies – for example, only when the connector is fully mated.

A similar connector shape does not guarantee safe compatibility. This also applies to solar connectors: use mating connectors explicitly approved for use together. Check whether a connector can be disconnected under load or whether the circuit must first be de-energised.

Cable routing: protect against abrasion, strain and heat

Good cable routing prevents cables from rubbing against edges, becoming trapped or pulling on their terminals as the vehicle moves. Plan suitable supports, edge protection and additional cable protection where needed. Keep cables away from hot components and moving parts.

Avoid tight bends and fixings that crush the cable. Heavy battery cables in particular need suitable support so their weight and movement do not place continuous strain on device terminals.

Protective sleeving and cable ducts must provide enough room. Consider heat dissipation too: enclosing cables in tightly packed bundles can reduce their current capacity compared with cables installed in free air.

Cable seals: check cable size, connector size and mounting surface

When routing cables through the roof or an exterior wall, choose a cable seal that suits the number of cables and their outer diameters. The specified sealing range is essential to ensure that the seal fits correctly around each cable.

If connectors are already fitted, their size matters too. The cable entry must either provide enough space for the connector to pass through or be specifically designed for installation with the connector in place. Split sealing inserts can make this possible where the particular design supports it.

Choose a design that suits the mounting surface and intended cable route. Low-profile or horizontal cable seals may suit different locations from vertical designs. Also check the specified mounting and sealing method at the vehicle surface: the seal around the cable does not automatically seal the mounting surface.

Distributing power and protecting connections

Busbars and terminal studs help you bring several cables together neatly. Check their current ratings, connection sizes and the space available for your cable lugs. A distribution point does not replace a fuse.

Cables and connected components need appropriate circuit protection. Do not choose a fuse solely according to the appliance’s power consumption; also match it to the cable’s permissible current capacity and the requirements of the connected devices.

Allow for covers over exposed live connections, particularly at the battery and positive distribution points. An organised layout and clear labelling also make future maintenance and troubleshooting easier.

Have these details ready before buying

• Application: Is the connection for 12/24 V, 230 V, solar or data, and will the cable be installed indoors or outdoors?
• Electrical load: What currents will occur, how long is the complete current path and what conductor cross-section is required?
• Connection sizes: Which stud sizes, connector contacts and conductor cross-sections need to match?
• Cable routing: Where do you need supports, abrasion protection, strain relief or a sealed cable entry?
• Additional materials: Do you have the matching connectors, contacts, covers and suitable tools for making the connections?

This helps you put together the installation materials your conversion needs and avoid discovering during the build that you are missing the right contact, cable seal or cable lug.