That attachment was very helpful.  I'm installing the trailer wiring harness on my 2008 edge.  Question:  on the left tail light, it says to splice into the violet/white wire at the tail light assembly.  There is a group of wires that branches out of the main harness and goes into the tail light.  There are 2 violet/white wires in this branch.  I don't know which one to tap into.  Or, do I tap into the main harness (I'll have to go back and look to see if there is only one violet/white wire there).  Any help would be appreciated.