7 pole RV plug/socket.
TerminalWire ColorFunctionLocation - Truck socketLocation Trailer plug1WhiteGround7:00 o'clock5:00 o'clock2BlueBrakes5:00 o'clock7:00 o'clock3GreenRunning10:00 o'clock2:00 o'clock4BlackPower2:00 o'clock10:00 o'clock5RedLT & Stop9:00 o'clock3:00 o'clock6BrownRT & Stop3:00 o'clock9:00 o'clock7YellowAux or BUCenterCenter
Here is a wiring diagram to go by.
Sorry the picture didn't come through.
Here is the link and I hope it comes through.