How to wire a 7-pin trailer plug

Updated July 19, 2017

Seven-pin trailer connectors are used on recreational vehicles and trailers. Over time, these connectors can become corroded and cause wiring problems, or become physically damaged, requiring a replacement. Parts are available online and at most auto supply stores, making this a good choice for a do it yourself project.

Loosen the screws on all the terminals on the back of your new seven-pin trailer connector.

Remove one wire at a time from the old connector and transfer it to the new connector. Be sure to install it in the same position on the new seven-pin connector. Remove the wires from the connector by loosening the screw on each terminal.

Install the wires by referring to this chart to install a seven-pin connector on a new trailer. Be sure to tighten the clamping screws securely.

Use the proper colour code to aid in troubleshooting lighting problems in the future.

Coat all connection liberally with dielectric grease to prevent corrosion.

Things You'll Need

  • Seven-pin trailer connector
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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.