3 Wire Trailer Breakaway Switch Wiring Diagram. These are commonly used for lighting in a stairway where you want a switch on each floor entering the stairway. I explain the wiring and test it.
SJ23 Tech Tip A08 - A Guide to Maintain Trailer Lights and ... (Eunice Webb)
The other two screw terminals on the switch body usually are brass-colored and are used to connect the circuit wires that run between the two three-way switches. But wiring a trailer may not be easy. You MUST follow the instructions exactly.
Perform the splice with a solderless butt connector.
I've been searching the internet for a wiring diagram that clearly shows how this needs to be done, but haven't come.
That said, and assuming that this is what you want to do, I'm going to refer you to any one of many DIY books on wiring so that you can look up an appropriate diagram, which I cannot easily do with my present PC setup. I will add my "Rules of Thumb for wiring switches" I use in my class. In this video, I replace my old worn looking trailer breakaway safety switch with a new one.