Thanks, I'm stil learning the DCC stuff.
It should be a 9-pin JST socket with a dummy plug that needs to be removed so you can plug in a decoder. Pull the dummy plug out and plug in any decoder that has a JST header on it.
I just purchased on e-Bay an Athearn 2-8-2 Light Mikado. I understand it was made a few years back. It has an umbilical that a decoder can be blugged into. Does anyone know who makes a decoder that will fit this plug or is the plug universal and any decoder can be plugged into it? It is not a 9 pin plug like I have seen. It is a mini connection type.