Diagram for 7-Way and 4-Way Trailer Wiring Connectors

Updated 11/18/2020 | Published 11/16/2020

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Question:

What is the wiring diagram for Rv to car 7 to 4 round

asked by: Donald Y

Expert Reply:

There is not an industry standard layout for wiring the 4-Way round pin connector, but there is a layout that is most accepted.

If you you are looking at the front side of the 4-Way round trailer side plug, the top left prong would be used for right hand turn signal and brake function, the top right pin would be the left side turn signal and brake light function, while the bottom left would be used for the tail light function. The last pin, on the bottom right would be used for the ground wire. See the picture to the right for more clarification.

I attached a picture of how a 7-way is wired up as well.

expert reply by: Jameson C