My trailer is original from 76',and the frame is boxed in, so it makes it pretty tough to rewire, as far as tracing anything, but I need to, so I was hoping someone could shed some light on the basics. My plug (that attaches to the truck)has four wires attached, green,yellow,brown, and white, but it is connected to 2 red wires, and 2 black wires ? Where they go I have no clue! I got under the trailer and all I could see is where the grounds are connected to the trailer. To make it even more confusing, when I pulled off the ten lbs. of electrical tape the last guy used on his custom instal I found the white wire from the plug(that goes to the truck) not connected to anything, and the two black wires coming out of the trailer attached to the brown wire from the plug that goes to the truck. Any help or diagram would be greatl. Thanks