Introduction

 Towbars Types

Type Approval

 Towbar Makes

 Electrics

 Accessories

A growing number of different types of towbar electrical connections are in use in the UK today. The electrics you choose depends on what you are towing as well as the electrics of the vehicle you are towing with.

The three different types of connections available are:

• Single Electrics
• Twin Electrics
• 13 Pin Electrics
  

And two different way of connecting them:

• Universal Electrics
• Vehicle Specific Electrics

Single Electrics

Single electrics (also called 12N electrics) provide you with a single 7 pin socket at the rear of your vehicle this is used to provide the normal tail/side lights, indicator, brake and fog lights. Single electrics allows you to tow any trailer or caravan as your entire road legal lighting is provided.

When fitting single electrics, depending on the vehicle you may have the option of:

• a Universal Single Electrical Kit
• a Universal Single Electrical Kit with By-Pass Relay
• a Vehicle Specific Electrical Kit

Twin Electrics

Twin electrics (the second socket is a 12S socket) provides you with two 7 pin sockets at the rear of your vehicle. This allows you to tow any trailer or caravan as your entire road legal lighting (including reversing lights) are provided.

The grey or white 12S socket provides power to the caravan battery, fridge, interior light and reversing lights and is optional when towing a caravan.

Many people who only tow a caravan for a couple of hours and will then be pitching up at a caravan site with mains electricity opt to do without the 12S socket and just fit single electrics to their vehicle.

When fitting twin electrics, depending on your vehicle and caravan you may have the option of:

• a Universal Twin Electrical Kit
• a Universal Twin Electrical Kit with Split Charge Relay and/or By-Pass Relay
• a Vehicle Specific Electrical Kit with 12S & Split Charge Relay Upgrade Kit or with a small amount of vehicles the kit comes as a twin kit.
  

13 Pin Electrics

13 Pin electrics have been the norm in Germany and most of mainland Europe for many years. The 13 Pin system replaces the twin electrical system currently used in most UK caravans.

There are plans afoot for the 13 Pin system to become standard on UK caravan. However the the date for the introduction of this has been delayed.

Currently 13 Pin sockets are usually fitting with some detachable towbars. This is because some detachable towbars have a swivel plate for the electrics to be hidden when not in use. The swivel pate is usually designed for only one socket.

Universal Electrics - for prices click here

Universal electrical kits are the way that towbars have been wired for years. They allow for connection to the vehicle lighting by use of snap connectors (eg Scotchlok's).

Using a tester you find the correct wire on the vehicle (for example the left hand side light) and then connect the black wire from the 12N socket to this using a snap connector. You would continue this with all the connections.

Audible Monitor

When fitting a universal kit some warning of indicator failure on the trailer or caravan is required under UK law. The Audible monitor is connected in series with the indicator connections and when the trailer is connected and the indicators are on it makes a buzzing noise to confirm that the indicator is working correctly.

By-Pass Relay

Since around the year 2000 vehicle manufacturers have been making vehicle lighting systems more complicated, requiring the use of by-pass relays when fitting universal electrical kits. It started with vehicles such as BMW, Mercedes and Audi and is now present in over 60% of new vehicles. Most of these are European vehicles, Far East and North American vehicles are now starting to require the by-pass relay.

Vehicles may have different reasons for requiring a by-pass relay. In fact many vehicles that we recommend be fitted with a by-pass relay will work without it. However if you get a fault on the trailer (and many people do) a high current in the trailer lighting system could cause very expensive faults to your vehicle.

However it is becoming more common for a by-pass relay to be required on vehicles. Even vehicles such as the current Vauxhall Vectra (2002-on) will not work with a universal electrical kit unless a by-pass relay is fitted.

There a small number of vehicles where a single by-pass is all that is required, but for most vehicles we recommend the fitting a 7 Way By-Pass relay. Some companies provide different types of 6 or 7 Way By-Pass relays, depending on the vehicle and whether single or twin electrics is being fitted, however we only use one.

7 Way By-Pass Relays include an Audible Monitor inside so no separate audible monitor is required.

Split Charge Relay

A self switching self combination relay is only used when fitting 12S electrics. The relay monitors the voltage in the vehicle and only provides power to the switched connections (see below) when their is sufficant voltage in the vehicle. This is usually about 30 seconds after the vehicle has been started (and for about 30 seconds after the vehicle has been switched off). This means that when towing with your caravan if you pull into the services for a meal you do not have to worry about the caravan leisure battery being fully charged and your vehicle battery being dead.

Five connections are made to the relay they are:

• Direct power feed (usually) from the battery
• Earth
• Switching Connection 1 (to 12S socket Pin 2) which charges the caravan leisure battery
• Switching Connection 2 (to 12S socket Pin 6) which supplies the caravan fridge
• Permanent Live Connection (to 12S socket Pin 4) for the caravan power supply

Vehicle Specific Electrics -
for prices see vehicle listings

We now offer over 300 vehicle specific electrical kits. These kits are designed especially for the vehicle they being connected to.

Most people refer to these as "plug in" electrical kits and in many cases they are. This means that even if the kits are a little more expensive the fitting is really easy.

However with some vehicles (such as most current Audi's and VW's) the vehicle specific kits are very difficult to fit and it is easier to wire using a universal kit.

Some vehicles are now being produced with options such as TSP ( Trailer Stability Programme). Functions such as these will only work if a vehicle specific kit is used.

The only other item you may require is a mounting plate for the electrical sockets (provided free of charge on request). No By-Pass relays are required.

Each of these kits is different please see are main price list and look up under your vehicle make.