Many motorists have trailers for transporting bulky goods in their household. In accordance with the current Highway Code, any towed vehicle (TLV) must be equipped with serviceable lights. The trailer is connected to the vehicle's electrical system via a plug and socket. To synchronize the signals of both vehicles, there is a universal trailer connection diagram and towbar socket pinout.
Contents
Connector types and connection diagrams
There are several types of automotive electromechanical plugs, including:
- 7-pin;
- 13-pin;
- 15-pin.
Some U.S. cars use four-pin connectors.
Semipin sockets can be of European or American design. In Russia, the European pinout is most commonly used. This wiring diagram of the socket for the trailer is not complicated, so most motorists make it on their own.
Wires are connected to the pins with screws. The numbering of the pins of the towbar socket is in a clockwise direction, and in the plug on the trailer - counterclockwise. Both parts of the connector have different types of contacts - sockets and pins. This is done to ensure safety when connecting the socket to the trailer in the dark.
Ways to connect the towbar socket
There are 2 ways to dock the wiring of the car and the trailer:
- regular;
- universal.
Regular connection is used if the car has a special socket designed for this purpose. The motorist only needs to connect the plug and the socket. If the latter is missing, it is necessary to dock the wiring of the towbar socket with a chip that fits to the regular socket. In this case, the driver does not interfere with the car's electrical circuitry.
In cars that have a factory connector, the pinout diagram can be found in the instruction manual. This connection option applies to some models of foreign cars. In most cases, the connection of the towbar socket to a domestic car is carried out in a universal (direct) way.
In models of cars that do not have an onboard computer, the work is reduced to connecting the wires of the towbar outlet to the wiring harness of one of the rear lamp units. Connection can be made with special clips or use soldering. The latter method is less time-consuming, and the connection of wires is more durable.
If your car's taillights are controlled by onboard computer, you will not be able to make a simple direct connection, because the car electronics will generate an error when the load increases when you turn on the lights. This can be avoided by making the connection with a matching unit. Then the corresponding signals to the lighting equipment will not come from the lamp unit terminals, but from the installed electronic device. With this connection method, the on-board electronics do not see the electrical equipment of the trailer.
Diagrams of different types of outlets
On domestic vehicles, most often installed electrical connectors for 7 pins. They provide all signals from the vehicle to the BTS. If a trailer needs to be connected instead of a cargo trailer, a 13 pin socket is used. For electrical wiring (pinout) use stranded wires in double insulation with a core cross section of at least 1.5 mm². To protect the harness from damage it is placed in a corrugated sleeve.
7-pin receptacle pinout
If the car does not have a regular connector for connecting the trailer, then install a socket, bought in the store, on a special plate near the towbar. In this case, the pinout is done in a universal way. To do this, the wires are directly connected by soldering to the corresponding pins of the contact pads of the taillights.
The pinout of the 7-pin socket looks as follows:
- 1 - left turn;
- 2 - fog light;
- 3 - "mass";
- 4 - right turn signal;
- 5 - reversing light;
- 6 - stop light;
- 7 - parking lights and license plate lights
On some European vehicles the rear fog light contact may not be engaged.
The control signals from the turn signals are taken from both sides and led to the socket with different wires. The indication of the rest of the lights can be taken from one unit of rear lights.
Pinout of a 13-pin socket
Most imported cars are equipped with standard 13-pin connectors. If the vehicle does not have a towbar, in most cases a 7-pin socket is installed. When one of the vehicles has a 13-pin socket and the other has a 7-pin plug, the connection is made with an adapter.
Unlike the 7 pin socket, the 13 pin socket has an additional 3 pins with a "mass" and 2 pins are used to supply power and 12V from the battery. 1 pin is left unused. Clearance lamps are powered through different conductors: each from its side.
To install a towbar on Niva Chevrolet uses a regular set of wires with end connectors that are connected directly to the contact chips rear lighting.
Pinout of 15-pin connector
This type of connector is used to dock towed vehicles with a tractor in most countries of the world. The connector not only provides the signal from the turn signal and brake light, but also sends back information to the truck driver about the status of the braking systems and controls some of the mechanisms of the PBX. Otherwise, the pinout is similar to the 13-pin socket. These electrical connectors are only used on heavy-duty trucks.
Direct wiring diagrams
This type of connection is used if there is no original terminal block in the vehicle. In this case, the wires are connected directly to the tail light harness. Connectors equipped with plugs for mating with optics can be used to facilitate installation. On the other side of the device there are wires for connection to the mating part of the device.
Before you connect the towbar socket, you must determine where to install the connectors. Connected to the lighting equipment through technological cut-outs designed for lamp replacement, and the output of the harness to the outside - through the drain in the bottom of the trunk. In some cases, the connection diagram of the socket on the towbar involves soldering wires. Such connections are more durable.
If you plan to combine two contacts, for example, the dimensions of the right and left side, then the common lead wire should be more than 2 mm², as the load on it will increase. You can purchase the necessary accessories in a store or at an auto market. You should not buy connectors and connectors homemade, as this is fraught with the occurrence of a short circuit with further ignition of the entire wiring.
Step by step connection to the machine
Before you connect the socket to the towbar, you need to prepare the following materials:
- a connector with a cover;
- connection blocks;
- color-insulated multicore cable with a core cross section of at least 1.5 mm²;
- protective corrugated tube;
- plastic clamps.
For a vehicle with on-board computer, you must additionally purchase a matching unit.
Work on the connection of the connector is carried out in the following order:
- Prepare wires of the required size.
- Remove the insulation and tin the ends or crimp them in brass sleeves. This will increase the strength of the connection and prevent heating.
- Attach the wires to the connector pins.
- Place the resulting harness into the corrugated sleeve.
- Attach the sleeve to the receptacle body.
- Solder the wires in the connection pads according to the diagram.
- Connect the latter to the connectors of the light optics of both lights.
- Lay the harness, secured with clamps on the body parts, and install the plugs on the technological holes.
After completing installation, connect the trailer and check the operation of the circuit. If there are no remarks, then seal the places of possible water ingress into the electrical parts of the connection with silicone. To prevent oxidation of contacts, lubricate them with technical vaseline or graphite grease.
Correctly performed pinout and installation will allow you to quickly connect the trailer, without wasting time checking the correctness of the connection terminals.
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