- seven-pin (7 pin) European-type connectors;
- American-type seven-pin (7 pin) connectors;
- thirteen-pin connectors (13 pin);
- special connectors.
The most common types of sockets have 7 and 13 contacts. In Russia, 7-pin devices are usually used, and 13-pin sockets can be seen on many cars from Europe and the USA. The difference lies in the use of additional contacts necessary to activate fog lights and other electrical components of caravans that are popular abroad.
Rules accepted throughout the world provide for the installation of left/right turn signals and stop signals on trailers for passenger cars. The connection diagram for a passenger car trailer socket depends not only on the number of contacts, but also on the standard of the country, so a trailer with European wiring cannot be connected to a socket with Russian wiring without modification. If you install it without modification, then the right dimensions of the BTS will not light up.
Direct connection diagrams
If the towbar and trailer of a passenger car (and truck) are equipped with the appropriate connectors, then the electrical connection diagram will not be needed at all, since you just need to insert the socket into the socket.
Pinout of 7-pin trailer socket Euro and RF
- Left side turn signal.
- Reversing lamp.
- Earth.
- Right side turn signal.
- License plate light and right side marker light.
- Brake light bulbs.
- Right side marker light.
US 7 pin trailer socket pinout
A special feature of the connector is the presence of a reverse contact and the absence of separation between the right and left rows of side lights. In some models of American cars, there is no separation between side lights and brake lights (they run on one wire).
Pinout diagram for 13-pin socket
- Left side turn signal.
- Rear fog lamp.
- Ground for terminals 1 to 8.
- Right side turn signal.
- Left side of dimensions and number plate illumination.
- Brake light lamp.
- The right side of the dimensions and number plate illumination.
- Reversing lamp.
- Constant voltage 12 volts 35 amps.
- The voltage is 12 volts 35 amps, supplied after the ignition is turned on.
- Ground for terminal.
- Signal wire.
- Ground for terminal 9.
Useful: iPhone battery connector pinout and battery replacement
When the car is not equipped with a modern electronic control unit. Thanks to this, electrical wires can be directly connected to existing electrical circuits. That is, the wires that come from the connector are connected to those connected to the rear lighting equipment.
Answers to 3 frequently asked questions about connecting a towbar socket
Even the cross-sectional area of the conductors is regulated, which ranges from 1.5 to 2.5 mm2 depending on the load consumed. The connection is required to ensure the safe operation of non-self-propelled trailers. This solution is a guarantee of safety when connecting a round connector in poor visibility conditions: the relative position of the sockets eliminates the possibility of their incorrect connection or short circuits. Carefully study the wiring diagram of the machine to accurately find the necessary circuits for testing, use a tester. Share with friends: You may also be interested. Types of connectors and connection diagram for a 7-pin towbar When planning to use a towbar for a trailer, you should install a socket and study the connection diagram for the towbar so that the corresponding signals through the towbar connector ensure that the rear turn signal lamps and other lighting devices are turned on.
The diagrams for connecting a trailer to the vehicle's on-board network are standardized, which allows you to install a tow bar with a socket once and then use it with any trailer. This allows you to connect electrical wires to existing electrical circuits without resorting to any splitters. This is much easier than replacing the entire connector on the car.
Fifteen-pin sockets are distinguished by wide functionality. It allows you to correctly supply power to all electrical equipment on the trailer. Option 1 This method is suitable for situations where the car does not have a modern control unit, which makes it possible to connect the wires directly to the electrical circuit. WE CONNECT THE SOCKET TO THE TRAILER WITH YOUR OWN HANDS.
Read more: Basic principles of energy saving in an enterprise
Electronic matching unit
If we are talking about a modern car with complex electronic components, the first option for connecting a trailer will not be the best choice. The control unit tests the rear optics. When it determines that it is consuming more current, it will display an error message. In such cases, the so-called “matching block” is used. It is also used in the case of transmitting control signals via a multiplex bus.
The wiring is connected to signal circuits, only in this case the signals to the lighting equipment of the towed device come not from the car, but from the matching unit, and its presence is not perceived by the electronics. Additionally, the unit must be connected to a used car.
The need to equip a trailer
Many manufacturers have recently stopped producing devices for towing old-style trailers. Such equipment, manufactured according to the latest standards, also requires new equipment. This includes a variety of signal lights that mimic vehicle lights.
Previously, drivers of any vehicle were not very interested in wiring diagrams for the socket on the tow bar. Because before they were not particularly intricate. The increase in products from China has changed the landscape of trailer wiring. Previously, conductors with one color were used for this. The process didn't take a ton of time or require a lot of effort. However, now we have to deal with the updated trailer plug connection diagrams, where the new conductors are multi-colored. It seems like it should be easier when connecting the wires. However, studying the diagram can sometimes cause headaches for a motorist.
What GOST 9200 76 says
All rules for pinout sockets for passenger car trailers, tractor equipment and vehicles transporting goods are determined by GOST 9200-76, which has been in force since 1976.
According to the document, the current standards accept the dimensions of the following trailer connectors and their equipment:
- 24 N – socket for the first contact and 6 pins;
- 24 S – 1-pin socket and 6 smaller pins;
- 12 N – 4 sockets for 1, 3, 4 and 6 contacts and 3 pins;
- 12 S – 4 sockets (1, 3, 4 and 6), a socket located in the recess and 2 pins for 2 and 5 contacts.
The document also assumes the fulfillment of technical conditions: the trailer socket with a plug must provide connection when supplying a current of up to 40 A. The designation of the connector equipment must be clear.
Electronic matching unit
The control unit of modern cars checks the operation of their optical system. If it detects that the current usage rate is exceeded, the unit gives a signal about it. In such situations, a matching unit is indispensable, which is also necessary when transmitting signals from the control unit using the vehicle’s multiplex communication.
The wiring must be connected to the circuits carrying the signal, otherwise the signals from the matching unit will not be able to travel to the rear lights of the towed vehicle.
Why do you need an electronic matching unit?
Thus, the coordination unit is a necessary link in the system, establishing communication between the vehicle and the tow hitch. Direct wiring connection in this case will not have any effect; the system will endlessly generate an error.
Principle of operation:
- Signals are transmitted from the vehicle to the towbar matching block;
- The received data is analyzed;
- If the system does not detect errors, then the signal goes to the vehicle trailer without any problems.
This scheme only works if the unit is connected to a battery. Correct work on connecting all wiring, taking into account pinouts, is an extremely important condition.
Materials for connecting the tow bar
We go to a car store or car market and buy the materials necessary for installation and connection:
- socket housing for tow bar with cover and rubber O-ring. We pay attention to the normal fit of all parts of the housing, the absence of play or the pressed brass contacts dangling in the sockets, we check the threads and the condition of the fastening screws on the terminals.
- high-quality single-core wire used in car electrical wiring, wire cross-section not less than 1.5 mm2; connection blocks, it is better to use a model with fuse sockets.
- polypropylene or metal corrugated hose for insulating wiring harnesses - 2-3 meters, and a couple of dozen plastic mounting clamps for fixing wiring harnesses.
- silicone gasket, choose color and manufacturer to suit your taste.
Features of the socket connection
To connect the towbar to the vehicle's electrical wiring, we recommend using stranded copper wire. The ideal option is a wire in which each core has a cross-section of at least 1.5 square meters. mm. The wire must have a double layer of insulation.
After connecting the trailer according to our diagram and checking the functionality of its lighting equipment, it is advisable to take care of protecting the internal elements of the outlet from moisture. It would be a good idea to use graphite lubricant, which will also prevent oxidation of the contacts.
Types of trailer sockets
When choosing a socket for a passenger car, pay attention to the types of products.
There are two types on sale (according to the number of cores):
- Seven-core (7 PIN). Designed to output external lighting sources and is used for standard cargo trailers. Such a socket, in turn, can be European or American (they differ in connectors). The peculiarity of the European circuit is that all seven wires are involved in it.
- 13-wire (13 PIN). Unlike the previous type, additional connectors are used here to allow you to connect a caravan trailer and ensure the functionality of all lighting and additional equipment (refrigerator, battery charger, etc.). So, to charge the battery, there is a separate conductor, which goes from the machine’s power source to the towbar socket and is protected by an individual fuse insert.
The 13-wire socket has more functionality and is suitable for many cars from the United States or the EU. But purchasing it will cost a lot, and connecting it will require a higher level of skill.
Sometimes situations occur when the car has a 7-pin socket and the trailer has a 13-pin socket (or vice versa). This is not a problem, thanks to the availability of adapters from 13 to 7 or from 7 to 13.
