The above diagram shows the wiring for the actual plugs, but it sounds like yours ripped out of the box itself that's attached to the trailer. Don't loose heart! With those 7 wires you have only 5040 combinations! I'm sure you'll eventually get the right combination!
I'm not sure what kind of junction box you have. On mine, it's just a standard house-hold junction box used in electric wiring. Each wire of the umbilical cord is attached to the trailer wiring with a wire nut. Kind of cheesy, but it works. I don't have the trailer with me at the moment to get a photo of the color code (although mine is a Montana, they are all still Keystone products). All I can suggest is to match colors the cord with this chart:
Jump to
This Page and down-load the color chart.