Est. 1951
Current Version J560_202002
Scope 7-pin 12V trailer connectors
Regionality North America

The standard SAE J560 for trailer connectors was originally issued in 1951 to create a standard in the commercial vehicle industry for the electrical wiring between heavy-duty truck and trailer. The latest revision is from 2020. Its purpose is to transfer the lighting signals as determined by the FMVSS (Federal Motor Vehicle Safety Standards) from the drivers cab to the trailer and to provide the trailer with continuous ABS primary power. The standard incorporates plugs, sockets and cables.

The plug for SAE J560 is physically identical to the trailer connector according ISO 1185. The difference is that systems according to the SAE standard run on 12V whereas ISO standard systems use 24V. Additionally, some of the pins in the connector fulfill different functions. The difference in voltage and current requirements makes the standards SAE J560 and ISO 1185 incompatible without the use of additional equipment in the form of voltage converters between trailer and towing vehicle.

Two types of 7-pin 12V connectors

The standard includes two types of connectors: Primary and Auxuiliary (AUX). Primary connectors are used to supply power to devices regulated by FMVSS 108 and FMVSS 121. Auxiliary connectors are used to supply power and control to auxiliary devices (i.e., lift gates, refrigeration power units, dome lamps, etc.). For a better recognizability, AUX connectors are identified by the color yellow and/or are permanently marked with “AUX”. Primary and Auxiliary connectors are not interchangeable due to an incompatible layout of pin 1.

Scope of SAE J560

This SAE Standard provides the minimum requirements for primary and auxiliary jumper cable plug and receptacle for the truck to trailer and converter dolly jumper cable systems for 12 VDC nominal applications. It includes the test procedures, design, and performance requirements.

Contact Allocation for Connectors According to SAE J560

 Contact no.FunctionCross-sectional areaCore insulation color
1Ground return to towing vehicle8 mm² / 8 AWGwhite
2Clearance, side marker and identification lamps3 mm² / 12 AWGblack
3Left turn signal and hazard lamps3 mm² / 12 AWGyellow
4Stop lamps and antilock braking system (ABS) (secondary power)5 mm² / 10 AWGred
5Right turn signal and hazard lamp3 mm² / 12 AWGgreen
6Tail and license plate, clearance and/or side marker lamps3 mm² / 12 AWGbrown
7Continuous ABS primary power/auxiliary devices5 mm² / 10 AWGblue
 Contact no.FunctionCross-sectional areaCore insulation color
8Ground return to towing vehicle8 mm² / 8 AWGwhite
9Cab switched auxiliary power3 mm² / 12 AWGblack
10ABS malfunction to cab3 mm² / 12 AWGyellow
11Constant or ignition auxiliary power5 mm² / 10 AWGred
12Unassigned3 mm² / 12 AWGgreen
13Unassigned3 mm² / 12 AWGbrown
14Unassigned5 mm² / 10 AWGblue