I had a trailer with the old 6 pin small round plug, and then bought a new trailer with that bigger 7 pin plug. However, I still had a big 22 ft gooseneck flatbed with the old style plug. So I had a little converter jumper that went from the 6 pin my truck to the bigger 7 pin plug. Every year , I tore my hair out trying to find out why sometimes the lights worked, sometimes the brakes worked, then other times nothing on the flat bed. Turned out those darn little mud wasp, got into the female end of the plug, laid eggs, and back filled with mud. I wasn't clever enough to see the plug wasn't going in all the way. I guess sometimes the mud feel out, some times it didn't. I finally found it when I took the female connector apart and saw the contacts pushed back into the housing.
I took all those old type connectors off and replaced with them all with the new versions and now I keep plastic bag on all the trailer connectors when not in use.
Last edited by saddlesore; 04/11/15.
