Manchester Towbar - Trailer & Roof Rack Centre

Tow bar electrics – Options we offer!

Contact: 0161 273 5816

There are three main options when considering which form of tow bar electrics you will need to go with the towbar on your vehicle.

  • Single 7 pin socket.
  • Twin 7 pin sockets.
  • Single 13 pin socket.

We offer the complete range of tow bar electrics to suit your requirements!

  • Single 7 pin black sockets cater for all the road lights on a trailer or caravan. Stop, tail, number plate, flasher,  front and side markers and fog lights. These are the minimum electrics allowed legally for towing or carrying cycles on the rear of a vehicle. They also are now included as part of an M.O.T. Test where a towbar is fitted  and need to be functioning.
  • Twin 7 pin sockets are for caravans which have two 7 pin electric plugs. The second socket is white or grey and is used to power internal devices in the caravan, mainly fridges, batteries and internal lighting as well as reversing lights. (Trailers do not have reversing lights fitted). These towbar electrics are not part of the  M.O.T. test. Please note; this option is not available on some detachable towbars where there is not enough room for the two sockets to fit behind the bumper when not in use. See below!
  • Single 13 pin sockets are now standard on modern caravans. The 13 pins cover all the functions of the above twin 7 pin sockets. This socket has a totally different pin configuration and can only be used on the single or twin systems by using inline adaptors. On detachable towbarsto tow caravans,  these sockets are standard. There are cases however, if requested, where we will fit  twin electrics but this can result in a larger bumper cut or even partial visibility of the sockets as there is not enough room for both to slide up behind the bumper. There is no problem however if only single 7 pin electrics are required.
  • Interface relays.     Many modern vehicles have engine  management systems installed. These are basically computers which tell the car what to do via pulses through fibre optic wiring. These computers activate different electrical and mechanical functions. The introduction of such high tech systems means that direct connection into the lighting system for trailer or caravan electrics is not possible and can cause expensive damage. To solve these problems special 7 way relays have been developed by the towbar trade. These relays bypass the vehicle computer and activate the trailer wireing from a remote source. This protects the vehicle systems and removes any malfunction of the on board computer.  The relay is working as an individual computer and it cannot be seen by the vehicle system.
  • Dedicated harnesses.    The alternative to the relays above are dedicated wiring harnesses. These are original equipment systems, wired into the vehicles computer. Thay activate all the functions set up by the vehicle manufacturer. Features including self levelling etc are enabled through the specialised relays incorporated in the harness, where applicable. With these devices fitted, the car knows it is towing. These harnesses are becoming more popular but are quite expensive to install and may have to be coded at the main dealer once fitted.
  • Split charge relays are fitted on twin and 13 pin electrics to protect the vehicle battery from draining flat while towing. They are designed to switch off the power to the battery charger and caravan fridge when the towing vehicle`s ignition is switched off. They come as standard on all our caravan twin or 13 pin fittings.