Connecting trailer lights: how does it work?

Connecting lights to your trailer can sometimes be very tricky. For example, there are different types of plugs and there are different types of trailers. In addition, of course, you want to prevent short circuits. We regularly receive questions about connecting lights to trailers and that is why we have listed the different wiring diagrams below, for the 7-pole socket and the 13-pole plug. With the help of the wiring diagrams it is possible for you to independently connect the lighting on your trailer. Furthermore, with the help of the wiring diagrams you can discover and solve any errors yourself.

Connecting trailer lighting

Trailer lighting diagram

In the market of trailer lighting we know three types of wiring diagrams, namely the diagram for the 7-pole plug, the 13-pole Jaeger plug and the 13-pole Multicon plug. Before we go any further it is important to explain the difference between the 7-pole and the 13-pole plug.

Connecting 7-pin plug

The 7-pole plug variant is suitable for less complex tow objects, such as a bicycle carrier, trailer, boat trailer or horse trailer. Using the 7-pole plug, it is possible to connect the basic lighting to your towing object. You can think of the basic lighting within the category LED rear lights (fog lights, turn signals and brake lights). Despite the fact that the socket with 13 poles is more extensive, the 7-pole plug still fully meets the set standards.

Connecting 13-pole plug

This variant plug can be seen as the big brother of the 7-pole plug. The plug with 13 poles is intended for more complex towing objects. For example, you can think of a caravan, an advanced trailer, a large boat trailer or a large horse trailer. Just like the 7-pole plug variant, this plug is also connected to your car. You can connect the plug to your trailer by inserting the plug in the coupling under the tow bar.

The difference between a 7-pole and 13-pole plug

The difference between the two plugs is that the 13-pole plug has more connections (and therefore more functions). A 7-pole plug will only supply the vehicle with basic lighting such as indicators and brake lights. The 13-pole plug, on the other hand, supplies the vehicle with power for several functions.

The extra poles on a 13-pole plug are used for reversing lights, as an extra constant current and as a switching current to earth, among other things. This extra constant current can be used, for example, for your caravan's refrigerator, for charging your battery or for electrically opening and closing your trailer box. If you need any of these functions, we strongly advise you to choose the 13-pole plug over the 7-pole plug.

Wiring diagram for trailer 7-pin connector

Wiring diagram lighting trailer plug/socket 7-pin universal 12 volt.

As the name partly gives away, the 7-pole plug consists of seven different connections. In the illustration below, these connections are indicated by different colors. Using these colors, in combination with the information below, you can easily connect your trailer's lights.

Seven connections 7-pin plug

  1. Connection/Pole 1 (color: yellow): Left turn signal;
  2. Connection/Pole 2 (color: blue/brown): Rear fog light;
  3. Connection/Pole 3 (colour: white): Mass (for contacts 1 to 7);
  4. Connection/Pole 4 (color: green): Direction blinker right;
  5. Connection/Pole 5: (color brown): Rear light/wide light and license plate on the right;
  6. Connection/Pole 6: (color red): Brake lights;
  7. Connection/Pole 7: (color black): Taillight/Broadlight on left.

7-pole plug connection diagram

For the 7-pole plug connection diagram, see the illustration below. All seven different functions are described in this picture.

Trailer pin assignment 7-pin

Wiring diagram for trailer 13-pole plug

Wiring diagram lighting trailer plug/socket 13-pole universal 12 volt.

Connecting a 13-pole plug is very easy with the help of the connection diagram above. As you can see in the illustration, this socket consists of thirteen different connections. As above, we will also explain the various plugs in the socket with 13-pole plug below. For the visual thinker we have also added a picture to be able to outline the complete picture in one overview. With the help of this diagram, you can connect the lighting to your trailer.

Thirteen connections 13-pin plug (Jaeger)

  1. Connection/Pole 1 (color: yellow): Left turn signal;
  2. Connection/Pole 2 (color: blue): Rear fog light;
  3. Connection/Pole 3 (color: white): Ground (for contacts 1 to 8);
  4. Connection/Pole 4 (color: green): Direction blinker right;
  5. Connection/Pole 5: (color brown): Rear light/wide light and license plate on the right;
  6. Connection/Pole 6: (color red): Brake lights;
  7. Connection/Pole 7: (color black): Taillight/Broadlight on left;
  8. Connection/Pole 8: (gray color): Reversing lights;
  9. Connection/Pole 9: (brown/blue color): Permanent power wire inside lights;
  10. Connection/Pole 10: (color brown/red): Charging cable for caravan battery/fridge;
  11. Connection/Pole 11: (color white/red): No destination (possibly ground);
  12. Connection/Pool 12: (-): No destination;
  13. Connection/Pole 13: (black/white): Ground (for contacts 9 to 12).

Connecting trailer lighting with the 13-pole plug to the trailer diagram (Jaeger plug):

For the 13-pole plug to trailer diagram, see the illustration below. In this picture, all thirteen functions of the Jaeger plug are described. With the help of this diagram, you can connect the lighting to your trailer.

Wiring diagram for 13-pin connector Jaeger

Thirteen connections 13-pin plug (Multicon West)

  1. Connection/Pole 1 (color: yellow): Left turn signal;
  2. Connection/Pole 2/54G (colour: blue): Rear fog lamp;
  3. Connection/Pole 3/31 (color: white): Ground (for contacts 1 to 8);
  4. Connection/Pole 4/R (color: green): Direction blinker right;
  5. Connection/Pole 5/58R: (color brown): Rear light/wide beam and license plate on the right;
  6. Connection/Pole 6/54: (color red): Brake lights;
  7. Connection/Pole 7/68L: (color black): Taillight/Broadlight on left;
  8. Connection/Pole 8: (gray color): Reversing lights;
  9. Connection/Pole 9: (brown/blue color): Permanent power wire inside lights;
  10. Connection/Pole 10: (color brown/red): Charging cable for caravan battery/fridge;
  11. Connection/Pole 11: (color white/red): No destination (possibly ground);
  12. Connection/Pool 12: (-): No destination;
  13. Connection/Pole 13: (black/white): Ground (for contacts 9 to 12).

Connect trailer lighting with the 13-pole plug to the trailer circuit (Multicon West):

For the 13-pole plug to trailer diagram, see the illustration below. In this picture, all thirteen functions of the Jaeger plug are described. With the help of this diagram, you can connect the lighting to your trailer.

Wiring diagram for 13-pin connector Multicon West

The difference between the 13-pole Jaeger plug and the 13-pole Multicon plug

Within the 13-pole plugs there are two different systems, namely the Jaeger and Multicon West system. When connecting a 13-pole plug, it is good to know that the two plugs have different poles. For this reason, we briefly explain the two plugs below.

Jaeger 13 pin plug

The new 'standard' plug is the Jaeger plug. This plug is equipped with a bayonet connection. This ensures that the plug is firmly attached to the socket and will not vibrate loose while driving. The bayonet connection is a valued connection because it significantly reduces the number of failures while driving.

Connecting the Jaeger plug with 13 poles is very simple. You insert the Jaeger plug at an angle of 90 degrees to the left into the multiple socket. In this situation, the fastening block is pointing downwards. When it is in the socket, you turn the plug a quarter clockwise. You then turn it into the socket and the bayonet connection is fixed. If you wish to connect the Jaeger plug with 13 pins to a 7-pin socket, this is possible with an adapter.

Multicon West 7/13 pin plug

In addition to the 'standard' 13 pin plug, there is also another model called the Multicon West plug. This plug fits in both the 7-pole and 13-pole socket. This makes the Multicon system usable as a 7 pole and 13 pole solution. This Multicon plug can come in handy when your trailer still uses an old 7-pin plug.

However, it is worth noting that the Multicon plug does not fit in a Jaeger socket , and vice versa. When we look at the use of both plugs, it is striking that the Jaeger plugs are used more often than the Multicon West plugs. The Multicon West system is found more often in caravans.

Different adapters to connect multiple sockets

Most vehicles today contain a 13-pole socket, while most trailers and bicycle carriers contain a 7-pole plug. To ensure that these can be connected to each other faultlessly, you use an adaptor. Adaptors come in different types. Below, we briefly explain the different adapters in our range.

Adapter from 7 to 13-pin

The 7-pin to 13-pin adapter enables you to connect almost any electronic product to the connector on your vehicle. For example, if you have a 13-pole caravan socket, but a 7-pole socket, you can convert it with the adapter. In short, the sales adapter from 7-pole to 13-pole plug is meant to be able to use a 13-pole plug, when your car is only equipped with a 7-pole plug.

You can find the matching product on our dealer portal via the following link: Adapter from 7 to 13-pin.

Adapter from 13 to 7-pin

The adapter from 13 to 7-pin plug does exactly the opposite of the above situation. If your vehicle is equipped with a 13-pole plug, you can use the adapter to ensure that you can still connect the 13-pole plug. Please note that only the 7-pole functions will work.

You can find the matching product on our dealer portal via the following link: Adapter from 13 to 7-pin.

Frequently asked questions about 7-pin and 13-pin plugs

At TRALERT® we regularly receive questions about the 7-pole and 13-pole sockets. We have therefore summarized these frequently asked questions for you below.

When do I use a 7-pin plug?

A 7-pole plug only provides the basic lighting. Think of the indicators and brake lights. A 7-pole plug is perfectly suitable for bicycle carriers, for example.

When do I use a 13 pin plug?

The extra poles of a 13-pole plug are used when, in addition to the basic lighting, you also use, for example, reversing lights and rear fog lights. These two options have been compulsory on trailers, caravans, boat and/or horse trailers since 10 July 2011. Since 2011, these vehicles have therefore been fitted with a 13-pole socket as standard.

What types of 13 pin plugs exist?

The 13-pole plug variant has two types, namely the Jaeger and the Multicon West plug. These are used for different purposes. Of the two, the Jaeger socket is the most common. Although the Multicon West is used most frequently in caravans.

More questions about the different sockets or connecting trailer lights?

Is your question not listed above and are you looking for a suitable answer? Then feel free to contact our technical experts. They will be happy to help you with all your questions about LED lighting, the wiring diagram for a trailer and the various connections that go with it.

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Ask us anything about lighting

We are happy to help you put together the lighting set for your vehicle.