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How to Wire a 4-Way Hitch to a 7-Way Trailer

by K.K. Lowell

Wiring a 4-way hitch plug to a 7-way trailer is not a difficult thing to do, but, it will not power all the circuits that are connected when the trailer is plugged in to a vehicle with a 7-pole connector. For long-term use, the connector on the vehicle should be replaced with a properly wired 7-pole connector; but for short-term use, such as transporting a newly acquired trailer, these connections are not difficult. Adapters are available to do exactly what this wiring does, but at much greater cost. So why not make your own?

Step 1

Connect the white wire from the male 4-way trailer plug to the ground terminal of the 7-way receptacle.

Step 2

Connect the brown wire from the 4-way plug to the running lights terminal of the 7-way receptacle.

Step 3

Connect the yellow wire from the 4-way plug to the left turn signal terminal of the 7-way plug.

Step 4

Connect the green wire from the 4-way plug to the right turn signal terminal of the 7-way plug.

Mount the 7-way receptacle to the underside of the tow vehicle bumper using self-tapping screws. Simply plug the 7-way from the trailer into the 7-way receptacle and the 4-way connector into the 4-way on the tow vehicle to use.


  • The electric brakes on a trailer will not be powered with this setup. You must allow adequate stopping distances to account for this. Accordingly, never haul a heavy trailer when connected in this manner. The breakaway brake will still function as normal, provided the on-trailer battery is charged and the breakaway cable is connected to the tow vehicle.

Items you will need

  • 7-Pole receptacle
  • 4-way male plug with pigtails

About the Author

K.K. Lowell is a freelance writer who has been writing professionally since June 2008, with articles appearing on various websites. A mechanic and truck driver for more than 40 years, Lowell is able to write knowledgeably on many automotive and mechanical subjects. He is currently pursuing a degree in English.

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