Which electrical kit to install for a towbar on a motorhome?

The question that almost always arises when installing a towbar on a motorhome is which wiring kit to use: Which wiring kit should I choose?

Basically, there is a difference between the polarity of motorhomes and cars whether you choose a 13-pin or a 7-pin wiring kit. We have already explained the differences between a 7-pin and a 13-pin wiring kit in detail on our FAQ pages.

Another difference is whether the electrics is vehicle-specific or universal. As with the number of poles, an explanation of the differences between these two types can be found in our FAQ section.

Whether you choose a 13-pin or 7-pin socket for the towbar depends on your personal preferences and the function you require. However, the choice of a vehicle-specific or universal electrical kit will have a significant impact on the cost of the complete installation kit, the cost of installation (whether do-it-yourself or in a workshop) and the difficulty of installation.

Questions are often asked about the cost of a motorhome towbar or whether you can install one yourself. We have several articles on this subject in our blog.

For a vehicle like the Fiat Ducato 250, the price difference between a vehicle-specific and a universal wiring kit can be more than 100 euros.

Vehicle-specific electrics

In general, a vehicle-specific wiring kit is quicker to install, but often needs to be activated to work. The cables are connected either in the cockpit area, under the seat, under the bonnet or to specially designed sockets in the rear of the car. Once activated, the electrical system is ready for use.

Universal electrics

With a universal wiring harness, the cables are connected directly to the vehicle's rear lights. Vehicles with a CAN-BUS system (almost all vehicles from 2004 onwards) also require a separate power supply. Once installed, everything works perfectly without the need for any activation.

Which cable set do I need for my motorhome - universal or vehicle-specific?

Now the question arises: Do I need a universal or a vehicle-specific wiring kit? The choice of wiring kit for your motorhome depends on a number of factors. We have summarised these as follows:

Install wiring kit yourself - regardless of motorhome type:

Our recommendation for do-it-yourselves is to choose a universal electrical kit. Such a kit can be installed by a do-it-yourself in about 30 to 45 minutes and requires no special tools or activation.

Have the wiring kit installed in the workshop - depending on the type of motorhome:

If the towbar is to be fitted by a specialist workshop, it is advisable to check beforehand. Opinions on electrics vary widely, even among specialist garages, especially in the motorhome sector.

Wiring kit for camper vans:

We recommend a vehicle-specific wiring kit for panel vans. Mechanics work faster with these kits and the installation costs are usually lower than with universal kits despite the activation.

Wiring kit for A-class, coachbuilt and coachbuilt with overcab bed

For A-class, coachbuilt and coachbuilt with overcab bed motorhomes, the choice of electrics varies from workshop to workshop. Depending on personal preference, our partner garages use either universal or vehicle-specific wiring kits. Despite the individual approach, the general advantages and disadvantages of both options cannot be ignored.

Vehicle-specific electrical kit

Installing a vehicle-specific wiring kit in a C-class, A-class or coachbuilt with overcab bed can be complicated by the length of the vehicle and the need to run the wiring harness up to the bonnet. Additional openings for the cables are sometimes required. These electrics tend to be more expensive, but have the advantage that they are perfectly matched to the vehicle, ensuring a consistent look and feel throughout the vehicle.

Universal electrical kit

Given the length of the vehicle and the effort required to route, the entire harness to the vehicle's main electrical box, the installation of a universal harness is a challenge. As coachbuilt and A-class vehicles are often heavily modified, the homogeneity of the electronic components plays a secondary role. Universal wiring harnesses offer the same functional reliability, do not introduce errors into the vehicle electronics and are quicker to install.

Purchase price differences - universal and vehicle-specific electrics

The table below shows the price differences between universal and vehicle-specific wiring kits for the most common motorhomes.

This table is intended to give you an initial overview of the price differences when buying electrical kits. Please note that it is valid at the time of publication and may change over time.

Conclusion

Choosing the right electrics for a motorhome towbar is crucial and depends on several factors, including polarity (13-pin or 7-pin) and whether the kit is vehicle-specific or universal. While do-it-yourselfers can benefit from the flexibility and lower price of a universal wiring kit, a vehicle-specific kit offers optimum integration and function but can be more expensive and requires professional installation. The choice should be based on personal preference, vehicle type and specific requirements to ensure safety and functionality.