Every couple of years I find that the trailer wiring connector (7 pin) on the back of my truck doesn't work properly, causing the brake or turn signals on the trailer to not function. This is caused because the wires and screw-down connection in the plastic housing totally corrode away over the course of 18-24 months. The visible side of the connector often looks ok (below). But, once that entire center section (with all the metal contacts) gets pulled out, you see nothing but corrosion.

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Is there a way to solve the corrosion issue? Or, more simply, is there a different style 7-pin connector that doesn't suffer from this problem?

2 Answers 2


I haven't used one of these, so I can't speak from personal experience, but this connector looks promising. I found a review of the connector, I have no idea how independent it is, but it goes into the build details.


When you install a new connector, coat the exposed metal surfaces with dielectric silicone grease. This will keep out moisture and slow corrosion. You can also just squirt the stuff in to the connector. It might be messy, but things will still work fine.

  • That was my first thought too, but the OP said that the connector looked fine and it was the back-end that was corroding. Dielectric grease might help if you can get it back in there, but it really sounds like a connector with a better, water-tight design, may be better. Mar 19, 2011 at 12:20
  • Good call. I think I might try to find a connector that can be packed with dielectric grease, then sealed tight against the elements. It really has surprised me just how bad these 7-pin connectors are, given that they seem to be a 'standard' connector.
    – JeremyP
    Mar 21, 2011 at 20:23

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