Review on 57661 7 Way Blade Electrical Adapter by Tim Thomason

There are 2 different 7 pin and 6 pin plugs - if one doesn't work buy another. I couldn't get my 6 way trailer to release the brakes after connecting my new truck with the 7 way adapter. I noticed that the trailer was incorrectly connected. I got another truck with another 6x and the trailer worked fine. I got another one from 7 ways from my tool box and it worked. I noticed that these 2 7 ways are not the same. I ended up buying a few more for my other trucks. As far as I remember it is somehow connected to the central pin.