Menu
You are here
Est. 1980
Current Version ISO 3731:2003
Scope 7-pin 24V trailer connectors
Regionality Worldwide
The standard ISO 3731 for trailer connectors was issued in 1980 as a supplement for the standard ISO 1185 from 5 years prior. The standards include a name affix to further define their area of application - ISO 3731 is Type S (supplemental) whereas ISO 1185 is Type N (normal). The purpose of the Type S connectors is to transfer signals and power for functionalities which cannot be served by the 7-pin Type N plugs and sockets (for example rear fog light or steady plus for a consumer on a trailer). The latest revision is from 2003. For a better recognizability, the housing of the supplementary system is white while the "normal" system features a black housing. Due to a different contact arrangement whithin the connectors, users can not accidentally plug a normal plug into a supplementary socket and vice versa.
Application of ISO 3731 Type S
When a trailer coupled to a truck necessitates more than just the basic lighting functions, the connector system according to ISO 1185 is not sufficient as the 7 pins cannot accommodate any further functionalities. The plugs and sockets according to ISO 3731 add 7 more lines to provide a steady power supply line for a consumers on the trailer (for example refrigeration trailers or semitrailers) or to control additional lighting functions (for example rear fog light or reversing light).
The supplemental socket is continually replaced by the 15-pin connector according to ISO 12098, which has been developed in the 1990s and which integrates the functionalities of the Type N and Type S 7-pin connector systems.
Scope of ISO 3731 Type S
The standard ISO 3731 specifies the dimensions of, and requirements for, 7-pole connectors of type 24 S and their contact allocation for the electrical connection of towing and towed vehicles with 24 V nominal supply voltage, thus ensuring interchangeability. A 24 S connector is intended to be used in addition to a 24 N connector according to ISO1185 where more than 7 poles are required.
Contact Allocation for Connectors According to ISO 3731
| Contact no. | Function | Cross-sectional area | Core insulation color | Designation according to DIN 72552 |
|---|---|---|---|---|
| 1 | Common return | 2,5 mm² | white | 31 |
| 2 | Reserved for future allocation | 1,5 mm² | black | |
| 3 | Reversing light | 1,5 mm² | yellow | |
| 4 | Permanent power supply | 2,5 mm² | red | 30 |
| 5 | Sensing device with common return | 1,5 mm² | green | |
| 6 | Power supply controlled by ignition switch | 2,5 mm² | brown | 15 |
| 7 | Rear fog light | 1,5 mm² | blue |
Scroll to to
Scroll
Update your location to see available products in your country.
Update your location to see available products in your country.
If you follow this link, you will leave the pages of Erich Jaeger GmbH + Co. KG. Erich Jaeger GmbH + Co. KG does not adopt the pages of third parties that can be reached via links as its own and is not responsible for their content. You can find more information on this in the privacy policy of the provider of the external website.
What are you looking for?
Search website
Search products
Select your language or region
(Current: English International)
Cookie settings
For the correct representation and function of this web page we use essential cookies. We also use third-party technologies to optimize our service. With accepting the Cookies,you agree to the use of these technologies. You may revoke or change your consent at any time with future effect. More information
ImprintPrivacy PolicyCookie-Policy
Cookie settings
For the correct representation and function of this web page we use essential cookies. We also use third-party technologies to optimize our service. With accepting the Cookies,you agree to the use of these technologies. You may revoke or change your consent at any time with future effect. More information
These cookies are necessary in order for the website to function correctly. These cookies are saved automatically when the website or a particular function is requested, unlessyou have disabled cookies in your browser settings. More information
These cookies are used to see how you interact with our website, which helps us improve performance and adapt the content to your interests. To do this, we use the services ofthird-party providers that receive information about your use of our website and may, for their own purposes, also combine this with other data that they have received from you andpossibly from elsewhere. More information
Privacy Settings
