2001 Factory Trailer harness woes

I have a 2001 Warnr Bros with the load leveling suspension. It came with the harness to plug in for a trailer. The problem was that there was no schematic to tell me what each color did. The smart person would have metered it but I just guessed and obviously I was wrong because I would randomly blow brake light fuses when towing my friends trailer last year. Now that I have my own trailer I really need to get this right. I did install one of those adapter boxes to handle the seperate brake turn bulbs...or whatever it is supposed to do but it is just not working right. Does anyone have a schematic or can tell me what the 6 or 7 wires in the factory harness do? Thanks ...my trailer is the flat 4 wire kind

I have put the trailer wiring harness here:

http://www.links-to-golf.com/van/trailer-wiring.html

Have fun!