COVID-19 Temporary Shut Down
In line with government guidelines and to protect our employees in all areas of the business we have decided to temporarily close our operations as of 12pm on March 26/03/2020 until further notice.
Whereas our website will accept orders please note that they will not be processed until normal operations resume. We will update our website constantly so please check back regularly.
We thank you for your patience and understanding at this time.
Team Witter & Westfalia
Wiring Kit FAQs
What is an electrical kit?
A towbar electric kit is the wiring set that connects the electrics in your car with the electrics on your trailer, caravan or bike rack.
What is the difference between a 7-pin and 13-pin electrical kit?
A 7-pin electric socket will power the lights at the back of your trailer or caravan, but not the inside of your caravan. A 13-pin socket will allow you to run the electric inside your caravan whilst you’re travelling.
What is the advantage of a 13-pin electrical kit?
13-pin electric sockets can be a little bit more expensive than a 7-pin electric socket, however, they do allow you to pump electricity throughout the interior of your caravan. This is important if you’re driving a long way to your holiday destination and would like to keep food or drinks cold. A 13-pin electric socket will also help you charge items like mobile phones, iPads and laptops.
What is the difference between a universal and a specific electrical kit?
A dedicated wiring kit is a specific type of electrical wiring designed for the specific make and model of your vehicle. A universal wiring kit will be suitable for most vehicle types.
What is a universal electrical kit?
A universal wiring kit will be suitable for most vehicle types.
What is a dedicated electrical kit?
A dedicated wiring kit is a specific type of electrical wiring designed for the specific make and model of your vehicle.
My car has a 13-pin socket and my caravan has 7-pin plugs. What adaptor do I need?
Adaptor part number ZEKZZ0004 is suitable.
My car has a 13-pin socket and my trailer has a 7-pin plug. What adaptor do I need?
Adaptor part number ZEKZZ0003 is suitable.
My car has 7-pin sockets and my caravan has a 13-pin plug. What adaptor do I need?
Adaptor part number ZEKZZ0002 is suitable.
My car has a 7-pin socket and my trailer has a 13-pin plug. What adaptor do I need?
Adaptor part number ZEKZZ0001 is suitable.
What is the difference between single and twin electrics?
There are 3 types of towbar electrics plugs, including single 7-pin electrics, single 13-pin electrics and twin electrics. Single electrics use one plug to connect your vehicle and trailer electrics, whereas twin electrics require two 7-pin plugs, which is usually necessary for towing older caravans or trailers.
What are 12N and 12S?
12N electrics provide the ‘normal’ legal lighting requirements, via a single 7-pin electrics plug. These include the brake, indicator and fog lights. 12S electrics provide the ‘supplementary’ or advanced electricals through an additional 7-pin twin electrics plug. The supplementary electrics include reverse lights, interior lights and power the fridge in a caravan. A 13-pin electrical plug combines both the 12N and 12S electrics in one plug and is more common on newer cars, trailers or caravans.
What is a towbar wiring bypass relay?
Rather than supplying a constant power source from the vehicle battery to the trailer or caravan, a bypass relay sends electrical pulses when a function is activated. For example, rather than sending a constant power supply to the brake lights, power will only be activated through the relay when you press the brake pedal and deactivated when you take your foot off the pedal. This way, power is supplied when it is needed, taking the strain off your car battery and also protecting it from potential faults that could occur from trailer wiring.
What is CANbus wiring?
CANbus wiring stands for controller area network and it is the internal communications network in the vehicle bus.
Are all 13-pin kits the same?
There are three main types of 13-pin kits:
Vehicle Specific 13-pin 12N function only:
- Essentially a standard vehicle specific kit with a 13-pin socket attached
- The kit provides Normal power supplied to the caravan/trailer for all legal light functions required for towing
- Indicators/turn signals, brake lights, fog lights and side lights
- The kit has no caravan supply feed
- The socket only contains pins 1 to 7
- Sometimes pin 8 for reverse is included
- This type of kit will soon be the standard and most popular vehicle specific kit
Vehicle Specific 13-pin with 12S preparation:
- Essentially a standard vehicle specific kit with a 13-pin socket attached
- The kit performs all light functions required by law but also has the facility for the 12S function to be added easily
- The socket usually contains all 13 pins and wires
- Pins 1-8 are fully operational as standard
- The kit requires a 12S extension kit to become a full function 13-pin kit, this is an additional cost
- The extension kit consists of a power supply wire, that requires routing to the battery, the relevant fuses and connectors and also a split charge relay that connects to a pre-prepared socket
Vehicle Specific 13-pin with full function 12N/12S:
- As the title suggests this type of kit has complete 12N and 12S functions
- The kit performs all Normal light functions required by law
- The kit provides a Supplementary power supply to the caravan for all the additional functions
- No additional kits are required
- Full connection details are provided
- This kit has full compatibility with the latest UK and European built caravans
What adaptors are available?
Connection adaptors are used to interchange between UK 7-pin systems and ISO 13-pin systems:
- Some twin adaptors do not contain full 12S function conversion
- Adaptors will become a key component as caravan manufacturers change to the ISO 13-pin system from 2008/2009 season
- Trailers and accessories will change around 2010
- There are four types of adaptor: ZEKZZ0001 - 13-pin to 12N/12S, ZEKZZ0002 - 13-pin to 12N, ZEKZZ0003 - 12N/12S to 13-pin and ZEKZZ0004 - 12N to 13-pin.
Can I fit the electric kit to my own car?
Modern electric kits come complete with instructions, but if you have any doubts you should always employ an approved stockist to install your electrics.
How often should I check my caravan/trailer lights?
A full light function check should be performed before towing.
How can I tell if the towing electrics are operating correctly whilst driving?
The electrical kit will send an electrical signal to the driver’s dashboard to indicate a failure. Please check your installation/product manual for more information.
What is an electric pre-fitting or preparation?
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.
What is a wiring harness kit?
A wiring harness kit establishes the electrical connection between the trailer and vehicle.
(FIN) Are the indicators at the rear of the vehicle and on the trailer not working?
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.
Was no C2 indicator light contained in the scope of delivery of my wiring harness kit?
The C2 lights function is generally included in the delivery scope of the cable set. However, if it concerns a Westfalia installation, these are not necessary and they are also not included.
What should I do if the control unit of my wiring harness kit buzzes?
If this happens, it is necessary to check whether your trailer has a rear fog light as the control unit recognises the trailer via the rear fog light.
What should I do if everything on the diode test device is illuminated in colours when inspecting the wiring harness kit?
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 watts. For this, one example of what we offer is a vehicle tester with a trailer simulation of 12 volts.