Towbar Electrics

You need this extension kit if you would for example like to tow a horse box trailer with interior lights or a caravan with fridge operation.

Optionally, there are extension kits for continuous power and charging cable. This is suitable for caravans with their own battery. This makes it possible to charge the battery during the journey.

The universal wiring harness kit is suitable for many vehicles without prepared wiring harness. For this, each cable must be individually connected to the vehicle’s rear lights with cable quick connectors. Every light function must be measured to the respective reverse light cable. The cable lengths are not tailored to the vehicle. In contrast, as a general rule, the vehicle-specific wiring harness kit is tailored to the respective vehicle in its cable lengths and cable plugs, Assembly of this wiring harness kit is simpler because the installation guide has been created for the vehicle and, generally, the plugs can be connected directly to the rear lights or particular nodal points.

Vehicles with a pre-fitting have a plug which is generally located horizontally at the rear of the vehicle. Here, the wiring harness kit can be directly adapted.

ESP refers to the electronic stability program.

The diode test device is not suitable for inspection purposes due to its low load bearing capacity being too low. It must be loaded with 21 watt. For this, one example of what we offer is a vehicle tester with a trailer simulation of 12 volts (900 001 300 198).

Parktronic is also referred to as EPH, PDC, APS, or simply as parking assistance. The space behind, and often also in front of, the vehicle is monitored and possible obstacles are visually or acoustically indicated as soon as the reverse gear is engaged. In the event of an acoustic signal, the frequency is increased (amount of time between sounds) the nearer the vehicle gets to the obstacle.

For a data bus (CAN) system, the wiring harness system is connected directly to the existing data bus system (CAN) in the vehicle. A defect on the trailer is displayed by the system already present in the vehicle. Through activation, other systems can be used such as PDC deactivation for trailer operation or trailer stabilisation. Installation of an indicator light is not necessary.

The data bus wiring harness kit is a digital system. Its function is similar to a computer network. The wiring harness system is connected to the “network” of the vehicle. In most cases, coding/activation is necessary.

This wiring harness kit is directly tailored for the respective vehicle. It generally has compact plugs which are connected to the corresponding rear light plugs on the vehicle, or connected at corresponding nodal points. In many cases, the socket is already completely connected. The cable length is always designed for the respective vehicle and the installation guide is specifically created for the vehicle.

The C2 light function is generally included in the scope of delivery of the cable set. However, if it is a Westfalia installation, they are not required and are not included. For electrical or data bus wiring harness kits, a C2 indicator light is no longer necessary as this is operated through an increase in flashing frequency. Therefore, this is also not contained in the scope of delivery.

The 13-pin wiring harness kit is already required for many new trailers (rear light is visible on the trailer). With this wiring harness kit, the possibilities are endless. You can use bicycle racks, caravans and, with a 7-pin adaptor, also small goods trailers. In addition, there is the option of for example using the interior lighting of a horse box trailer or a fridge in a caravan, by using the extension kit for continuous current and earth.

The electronic trailer stabilisation is a sub-function of the electronic stabilisation programme (ESP) (also DSC, DSCT ...). The system identifies a vehicle instability caused by an accompanying trailer at a non-adapted driving speed. Through the targeted reduction of the engine torque and suitable deceleration of particular wheels, the trailer is steadied. The trailer stabilisation thereby significantly contributes to an increase in driving safety.

A wiring harness kit establishes the electrical between the trailer and vehicle.

If the voltage-carrying cable which leads to the rear fog light has a voltage of 12 V after the light has been turned on, then the rear fog light is ground switched. For cars manufactured by Suzuki, Chrysler and Pontiac, a ground switched rear fog light may be present. You can check this by turning on the ignition and light and checking that the cable to the rear fog light already has a voltage of 12 V, whereas the rear fog light itself is turned off.

For models such as Opel Astra H and Zafira B built in or after 2004, the so-called REC (Rear Electric Centre) is located under the left side panel in the boot. This is a control unit pre-fitted for the insertion of a trailer control device.

For models from the Ford range, this denotes a preliminary set-up of the CAN cable ex works, which is located on the right at the rear under the cladding.

If this is not present for Ford models, then you also need an additional cable set.

Please contact your dealer for this.

It is always important to check whether your vehicle possesses the preliminaries mentioned above, as some cable sets are different, or additional cable sets are required.

Here, it is necessary to check whether your trailer has a rear fog light, as the control unit recognizes the trailer via the rear fog light. If it is not present on the trailer, it must be fitted later.

If you have used a wiring harness kit and the error indication mentioned above appears, the reason for this is usually a lack of continuous power supply from the additional relay. Please check this.

Equipment in a vehicle which monitors the lights and indicates any possible malfunctions is referred to as check control. This notification either takes place visually or acoustically and can be contained in information displays or car computers. Because, for these vehicles, the trailers must be operated independently from the vehicle lighting, so-called wiring harness kits for check control or extendable wiring harness kits with check control interfaces are necessary in order to rule out damage to the vehicle electrics. Wiring harness kits with check control interfaces must, in the presence if a check control system, be expanded with an extension kit.

As a general rule, the 7-pin wiring harness kit is used for smaller goods trailers. It is not possible to connect the reverse light. For the 13-pin wiring harness kit, the reverse lights, continuous current and charging cable on the trailer can be used. This wiring harness kit is suitable for horse box trailers, bicycle trailers and caravans.

The C2 indicator light must be installed within the driver’s field of vision, or is already integrated into the vehicle’s dashboard. It is responsible for monitoring the trailer’s direction indicators in correspondence with the statutory provisions. The function and failure of the trailer’s direction indicators is signaled by it working together with the original indicator lights.

It is a wiring harness kit that is suitable for several vehicle types and can be connected to the rear lights by means of cable quick connectors. In doing so, there are no prepared plugs available. For this, each individually required rear light cable must be connected to the cable harness of the wiring harness kit by means of cable quick connectors. The socket's pins must be individually bolted to the cables of the wiring harness kit. The universal wiring harness kit is suitable for nearly all vehicles that do not have a prepared wiring harness. The cable length is thereby sufficient for nearly all vehicles.

The flashing units, often also called “flasher relays”, controls the flashing impulse to the vehicle’s indicators and, where applicable, to those of the trailer. Errors in their function are indicated through a change in the flashing frequency on the indicator lights. As a general rule, the flasher unit is incorporated into the central electrics, but can also be combined with the hazard warning switch and other control units. For operation with trailers, the original flasher unit is, in combination with a relay wiring harness kit, replaced with a flasher unit with C2 function and an additional control is installed. There are flasher units with the various connection assignments which, in the event of the installation of a C2 flasher unit, must be partly adjusted using adaptors.