My trailer lights on my 2002 ford explorer are not working. The plug atachment is the one from the factory. It has the round plug with 6 prongs and one in the middle. It worked two weeks ago but now it is mysteriously not working. I tried another plug adapter but that did not work so I bought one of those cheap plug testers at Wal-Mart and the only thing I can get to work is my tailights when I turn my headlights on. I checked the fuse under the hood and that is fine. So if anyone knows anything about newer ford explorers, please help me out. Thanks!