4-pin to 7-pin - where's the pigtail?

[cs jeff]

I have a 2004 EB and it came with the front plug-in for a trailer brake and it has the 4-pin connector in back. I have converted it to 7-pin for my trailer, but i cant find the pigtail under the car to hook up the trailer brake (blue wire plus 2 others). The U-Haul guy that sold me the brake controller said its usually tied off underneath along the frame rail but i cant locate it. Anyone know specifically where it is?

 

[ELVATO]

Does this thread help?
http://expeditionforum.com/showthread.php?t=3930

 

[cs jeff]

I saw that, but I'm looking for the pigtail that is supposedly somewhere along the frame rails. I have the 7-pin wiring harness and the brake controller plugged into the factory plug under the dash. Everyone says that the extra wiring is there and looped and taped under the truck somewhere. I just cant find it...