If it were me, I'd import a 13 pin plug for the trailer and re-wire it. That's going to be the cheapest and best fix and gets rid of all the adapters.
If you're not electrically adept you might need a hand from an auto sparky or a friend that knows how to use a multimeter.
It might be that the trailer isn't wired to a standard too, there's a few different ways to wire those up.
Perhaps converting the trailer to large 7 pin might address the issue.
Bookmarks