How to Determine the Function of Trailer Connector Wires

Updated 04/01/2013 | Published 03/29/2013

Question:

I HOOKED tHE BATTERIES TWO MONTHS AGO they were dead i put in two new ones today. no problems putting the black and white wires in the right spots but there is another orange wire coming from the trailer not marked where does it go which post? thanks

asked by: Paul C

Expert Reply:

Since color coding on trailer wiring is different for almost every manufacturer you have two options for determining what wire goes where for wiring in a trailer connector.

You can either trace the wires back and see where they terminate to determine their function, or you can use a 12 volt battery like a vehicle battery and a jumper cable to apply 12 volts to each wire and see what trailer wiring function is activated and then wire it to the 7-way accordingly.

I attached a picture of how 7-ways are typically wired.

I also attached an FAQ article on trailer wiring for you to check out also.

expert reply by: Jameson C