I would say your best bet would be to get a test light and start in! the center for your 6 pin is for a constant HOT wire. You should be able to do away w/ the Purple as I think that is the Reverse lights. tape it back (after you check to make sure it is)
I found this too!
Trailer Wire Post
try that out! there is a link to a diagram on that post as well!
I found this too!
Trailer Wire Post
try that out! there is a link to a diagram on that post as well!