Tow Bar Electrics

Tow bar electrics are reasonably easy to understand but, on today's cars, no longer easy to install.

Most modern cars have what are called multiplexed or CANbus wiring harnesses which, in simple terms, means that the wires have shared data and signals travelling on them.


Consequently, on multiplexed vehicles it is no longer possible (or recommended) to simply join the vehicle's lighting wires to the seven core trailer wiring.


Call The Experts


Get in touch with us today – call us or send an email and we'll advise you on the best tow bar electrics to make sure you're driving legally, you have power to your caravan if required, and then you're not draining the car battery when the fridge or leisure battery are requiring power.


Bypass or Dedicated Towing Circuits


There are two ways of efficiently and correctly addressing the complexity of the modern wiring and that is to install either a bypassed or dedicated towing circuit into the vehicle.


A fully bypassed system creates, using a sophisticated relay, its own towing circuit for distributing the trailer lights. The vehicle is unaware that it is present and it cannot therefore interfere with the car's many electrical functions. The relays we use are extremely reliable enabling us to offer comprehensive guarantees and have not only audible bulb failure monitoring but a fog light cut off on the towing vehicle to prevent glare when a trailer is connected. We believe, and our fitting history confirms, we install the most reliable bypassed system available today.


Dedicated Wiring Kits


Not many modern vehicles actually have full on board trailer stability programmes or features which control suspension settings etc. and therefore we only recommend our customers do not have a bypassed system installed, as a first option, where the vehicle DOES have some or all of these features. (BMW X5, Range Rover and Discovery for example) or, of course, where the customer (dealer or owner) specifies it.


Our experience shows that the less a tow bar circuit is interfaced with the vehicle's own electrics, the less problems are encountered. Fact!


There are, however, a full range of OE and dedicated towing kits available usually catering for 7 or 13 pin outlets, many now from UK makers with full function supplementary power kits available. EECO, who install for local car dealerships, have been fitting dedicated wiring since multiplexed wiring became prevalent, but it is not always necessary or the best and most cost effective option.


If we are fully guaranteeing our installations our customers should be aware that we would naturally only fit what was the most economic or beneficial for their needs. We always discuss the choices with you unless you are clear as to your requirements. We will never sell you something you do not need.


Remember, the quality of the components, the guarantee given and the experience of the installers is your peace of mind that the correct type of wiring is being used, not what you might have read or been told by your dealer!


Having ascertained what type of electrics are to be installed, it is only necessary to know what you will need your tow bar for. What will you be towing? There are basically three options:


7 PIN 12N (Single Socket)


Anything can be towed with these electrics as it supplies all the legal requirement for road lighting.


Usual use is small camping trailers, horse boxes general trailers and bike carriers.


A black socket with black cable.


12N / 12S (Twin Socket Electrics)


This has two electrical sockets. A black capped one that contains all the road lights as described above and a light grey capped one with grey cable that contains supplementary power for caravan use. This circuit will have a voltage triggered combi charging relay incorporated and this basically ensures that the power to the caravan cannot flatten or compromise the vehicle's battery when drawing power. Power is used for the leisure battery and fridge in the caravan.


13 Pin Electrics


This is the continental style of outlet becoming increasingly adopted in the UK now, and it usually contains all that of the twin socket above, but in a "push and twist" 13 pin format. A 13 pin socket can, of course, be installed with only seven pins (road lighting) operable for certain bike rack applications.


Call Us Today


Call us today and we will, without obligation, clarify any questions or details you may have about towing electrics. Your vehicle electrics are complicated and should only be modified by qualified and experienced installers.