My 06 does not have the 7-pin either. I am posting some instructions i got on this site or another one - but don't remember who gave them to me to give them credit. I have not done mine yet and not sure if I will, but here are the instructions. Hope it helps, Mike. I it is someone on this forum that gave these to me - please speak up and take credit.
A little more detail:
What I did to convert 4-pin to 7-pin trailer connector on a 2004 Expedition:
• Removed 4-pin connector from hitch (just slides out)
• Cutoff 4-pin connector bracket from hitch (ground down two small welds)
• Welded 7-pin connector bracket to hitch
• Painted entire hitch black
• Attached 7-pin connector to bracket on hitch
• Cut and strip wire feeding 4-pin connector (Note: This step could be avoided as some 7-pin connectors have a 4-pin connector input) Just plug in, I preferred to splice the wires together.
• Splice or attach the five wires to the 7-pin connector to the proper pins (Green, Yellow, White, Brown & Blue) Note: you may want to upgrade the white ground wire to 10 gauge (just like factory 7-pin)
• Look under the drivers side rear door, you will find two wiring harnesses there
• The smaller harness has an Orange wire going in one end of the harness but does not continue after.(pin12) This is the 12v lead
• Splice into the wiring harness orange wire and wire back to the 7-pin connector. I used 12 Gauge wire and protected it with wire loom.
• Note: The larger harness has a black/light green wire going in one end of the harness but does not continue after.(pin8) This is the reverse backup light wire if you want it. I did not so I did not wire.
• I then tye wrapped all the wires up and out of the way being careful that the wire does not get caught up in the rear suspension or spare tire movement.
• Remove fuse panel cover from front passenger foot area
• Install standard automotive type 30-amp relay into slot R05
• Install 30-amp maxi fuse into slot 106. I found a spare in slot 105
• Replace fuse panel cover.
• Connect brake controller wiring harness under the dash to your brake controller
• Checked all 7-pins with a meter to be sure I wired all correctly.
That’s all I did and everything works great. I have got trailer brakes and switched 12volt power in my travel trailer now.
Parts list:
• 7 pin connector (I got one with both 7 pin and 4 pin connections)
• 7 pin mounting bracket
• 30amp standard automotive relay
• 30amp maxi fuse (there was a spare in my fuse block that I used)
• 12 gauge wire from pass floor connector to 7 pin (12v lead)
• Wire loom to protect wire
• Trailer brake controller adapter for Ford Vehicles
All parts are available from just about any automotive store.
I don’t recommend trying this unless you are familiar with wiring.
