How to Replace 7-pin Trailer Cord Socket

Need to to replace 7-pin trailer cord socket? Here’s another quick RV maintenance tutorial for those who like to save a few bucks on simple repair projects. Complete with photos, detailed steps, and a little history…

7-pin trailer cord outlet

We first wrote about the broken retention cap for our fifth wheel trailer umbilical cord—and how we fixed it on the cheap—back in 2008. I finally decided to replace the 7-pin trailer cord socket in the bed of our Dodge Ram 2500 pickup after finding one amongst the many bargain bins at Quartzsite.

Steps to Replace 7-pin Trailer Cord Socket

If you are even the slightest bit handy with a screwdriver, you can replace the socket for your trailer tow lights/brake wiring harness by following these simple steps.

7-pin trailer cord socketYou will need:

*Make careful note of your specific trailer cord socket model. 

1. Remove the four screws securing the socket to the truck bed. Gently pull the socket and cord out far enough to comfortably work on it.

(Travel Trailer Owners: Follow the same procedure for bumper-attached sockets. Fifth wheel owners should always consider adding a socket inside the bed of the truck to avoid having the cord drape over tailgate.)

replace 7-pin trailer pin outlet

2. Remove two small screws from side of socket, and screw plug securing wires at the bottom to release the wiring harness.

7 pin rv trailer cord socket

3. The plug assembly should be clearly marked to indicate what color wire attaches to which post.

(Note: If the plug poles are not clearly marked, or different colored wires are used, be sure to mark them carefully or take a photo for reference.)

fix rv trailer cord socket

4. Remove all wires and twist the ends to create firm connections to the new plug assembly. NOTE: Slide all wires through the new socket housing from the bottom before proceeding!

seven pin trailer cord wires

5. Securely attach center wire first to the new plug, followed by all other colors in their corresponding positions.

(Optional: I prefer to make small loops with each wire to guarantee a secure fit and maximize surface area of each connection.)

7-pin rv trailer cord socket wires

6. Insert plug assembly with wires attached into the socket housing. Note the position of the notch on the side.

rv tow trailer cord socket fix

7. Important! Align notch in plug assembly with tab in socket housing and firmly join the two together. They will only fit together one way.

7-pin trailer cord socket

8. Attach plug assembly to the socket housing with two small screws on side and secure wires at bottom with threaded plug.

9. Reinsert the reassembled socket into your truck bed or bumper bracket, and secure with provided screws.

7-pin trailer cord socket

10. Use the spring-loaded outlet cover to secure your trailer cord into the socket. (See what we did to secure our cord for the past few years after the spring broke.)

rv trailer tow cord truck bed socket

Epilogue: Always remember to unplug your trailer cord before pulling away with your truck after unhitching to avoid braking the socket!

Need to replace the 7-pin trailer plug at the end of your cord? That should be just as easy following similar steps.

Also See:

How to Repair 7-pin Trailer Cord Plug

How to Fix Trailer Tail Lights Not Working

Keep that cord plug covered!

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