Hello I posted yesterday about this. I found bundle today. It is under the brake pedal to the left of the pedal.,I removed the panel below the steering wheel to allow a trouble light. The bundle is to the left of a metal box about 4in by 2 in, and next to this box is a metal plate above where your left leg would be. The 4 wire bundle is taped to another bundle of wires about 3/8 in diameter. You have to delicately remove the tape (which also has the upfitter switch color codes). The other problem is that they only give you about 3 inch pigtail to work with. At least I finally found them, now how to figure out splicing to a 3in pigtail with little working space.
450Lariat