Guys I dont know what is going on here, running lights work, but no brake lights, and no turn signals. If I turn the running lights on , they all light up, but no "brighter" brake lights, and no turn??? I have checked every ground on the trailer, grinded down to bare metal and replaced ground for ground screw. Even grinded down the surface that the tail lights attach to, checked every fuse in the trcuk, none blown? Any ideas please help!? I know the bulbs are dual purpose bulbs just had to replace them, even swapped them with some bulbs from old trailer lights that I know worked..