Wasn't sure exactly what the junction box is called. I know where the trailer box plugs in on my 04. But my question is what is the black plug to the left of the trailer brake box plug? Most hummer a have one but mine does not. Just wondering what plugs in there. Thanks

 

dont know what you are talking about, post a pic

 

The top left black plug The white is the trailer breaks/offroad lamp which I have. I do not have the black plug. Just curious as to what it runs to.