TOWING ELECTRICS

If you are towing a trailer / caravan / trailer tent / folding camper or using a cycle carrier / towbar mounted cargo box you will require electrics installed on your towing vehicle to operate compulsory road lighting functions on the attached unit. 

You may also additionally require the operation of internal 12v equipment (fridge / battery charging) and activation of ATC systems, where these features are installed / available. 

To accomplish this there are fundamentally 4 different types of towing electric sockets used in the UK:  

12n electrics, also referred to as 7pin or single socket electrics.

This system is used to operate the basic road lighting functions on caravans (pre 2010) and a large range of trailers and cycle carriers.


The pin functions comprise of:

  1. Left hand indicator
  2. Fog light
  3. Earth
  4. Right hand indicator
  5. Right hand side lights
  6. Brake lights
  7. Left hand side lights

12s electrics, used in conjunction with 12n electrics on pre 2010 caravans. This system operates the caravans 12v internal functions while towing and also caravan reverse lights.


The pin functions comprise of:

  1. Reverse lights
  2. Switched supply for battery charging (pre 2000 caravans)
  3. Earth
  4. Permanent live 12v supply
  5. (not used)
  6. Switched supply for fridge
  7. Earth

13pin electrics are used on some trailers and cycle carriers for road lighting functions only.


The pin functions comprise of:

  1. Left hand indicator
  2. Fog lights
  3. Earth
  4. Right hand indicator
  5. Right hand side lights
  6. Brake lights
  7. Left hand side lights
  8. Reverse lights

13pin electrics, installed as standard on UK caravans from 2010, can be used for road lighting functions and for the operation of auxilliary 12v supplies. Some trailer tents may also use this system.


The pin functions comprise of:

  1. Left hand indicator
  2. Fog lights
  3. Earth
  4. Right hand indicator
  5. Right hand side lights
  6. Brake lights
  7. Left hand side lights
  8. Reverse lights
  9. Permanant live 12v supply
  10. Switched supply for fridge
  11. Earth
  12. (not used)
  13. Earth
Once the decision has been made as to which type of socket is required the next process is the connection and integration of the towing electrics to the vehicle. 
This can be accomplished in two different ways by using either vehicle specific (dedicated) electrics or universal wiring systems.

Vehicle Specific (Dedicated) Electrics.


Advances in automotive electronics have meant the introduction of numerous comfort and safety functions into motor vehicles. In many cases not only have the vehicle manufacturers designed their vehicles to detect a trailer or caravan but to also change the way these systems operate and how the vehicle functions when towing.


These changes may include:

  • ESP becoming 'TSP' to help correct trailer 'snaking'
  • Brake electronics 
  • Suspension systems
  • Engine electronics
  • Parking aids
  • Engine cooling systems
  • Cruise Control/Active Cruise Control
  • Lane change assistant
  • Side Scan


Vehicle specific (dedicated) wiring kits have been designed, where possible, to replicate as closely as practicable, the vehicle manufacturers systems.

Vehicle specific towing electrics are only available in 12n (7pin) or 13pin* configurations. 

Trailer indicator warning is usually accomplished by utilising the vehicle manufacturers inbuilt warning system or an audible tone if an indicator fails.

If you have a 13pin system installed on your vehicle but need to tow a trailer tent/caravan with twin electrics (12n/12s) this can be accomplished using an adaptor lead*

The vehicle may also require coding with dedicated diagnostic tools to activate towing features.**

Towcraft carry out the necessary coding to most vehicle's during the installation process.


*may not be fully compatible with pre 2000 caravans.

**only with vehicle specific wiring kits.


UNIVERSAL ELECTRICS

Universal wiring kits are available in 7pin (12N), 7pin (12S), or 13pin configurations.

They can connect either directly or via a 'bypass relay' to the vehicles wiring harness.

Trailer indicator warning is usually achieved by means of an audible unit.

Universal electrics will power all trailer / caravan road lighting and optionally caravan 12V internal equipment but will not activate any towing related features on the towing vehicle.

Universal electrics are usually cheaper than a vehicle specific wiring system.

Universal electrics are not compatible with all vehicles.

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