Hopkins 7 Pin Trailer Connector Wiring Diagram. Repeat this process for both turn signals. Seven-pin connectors are rarely used on trailers for local use.
It is viewed from the rear of the connector. Note - left turn, right turn, and brake lights work. Seven pole connectors are typically used with large trailers (RV and industrial).
Definitely looking for a "plug and play" type.
A number of standards prevail in North America, or parts of it, for trailer connectors, the electrical connectors between vehicles and the trailers they tow that provide a means of control for the trailers.
Without a factory wiring diagram, I don't know where else to look. Refer to your trailer service manual and plug installation instructions to avoid wiring problems that may. Maybe someone could go to a dealer and ask to look at the wiring diagram.