Hi all... I know this thread has been dead for a while, but it comes up at the top of a google search so I thought I'd throw in my method for adding steering wheel controls here rather than start a new thread.
After doing some research I found that you cannot simply go buy the steering wheel harness that connects the clockspring to the left and right steering wheel switches; it is only serviced with the steering wheel. I came up with a method that will allow you to build your own harness on top of what is already there. This is pretty cheap as you only need to buy 2 things: the switch and a Ford pigtail kit.
*Note this was all performed on a 2007 Sport Trac. Your wiring could be different. I cannot be responsible for any damage you cause to your car!!! Be careful when working around airbags. They can injure you. Get someone with experience to help if you don't know what you're doing!!*
Items needed:
1) RH steering wheel switch: I chose to use part number 6L2Z-9C888-GAA (SW-6292 motorcraft). This switch also includes the temp + and - function. I don't actually have EATC but figured I might come up with something else to use that switch for in the future. I also have the part number for the switch without the temp control but forgot it at work so if anyone needs it let me know.
2) Wiring pigtail part number 3U2Z-14S411-DAAA (motorcraft WPT-699) this is the connector C2208 that plugs into the RH steering wheel switch.
3) Soldering iron, solder, electrical tape, tools, etc...
This job does not take long. I started by removing the airbag. There is no real need to unplug any connectors from the airbag, just lay it on top of the steering wheel. To be safe disconnect the battery and be sure the airbag is disabled and so on. Once the airbag is out of the way, unplug the steering wheel harness from the clockspring, remove the screw on the grounding terminal, unplug the horn connector and the cruise switch. Remove the harness from the steering wheel.
The awesome thing about the WPT-699 wiring pigtail is that it has all eight wires installed and they just so happen to be the same terminals used in the clockspring connector! You only need four of them at the RH switch: the power and ground for the lighting and the two audio control wires. So we remove the four un-needed wires by removing the red locking tab and releasing the pins (I use an xacto knife to release the tabs.)
Wire removed:
The removed wires are added to the clockspring connector by removing the red locking tab on the connector and inserting the terminals. In my case I removed pins 2,3,4,and 8 from the pigtail and installed 2 of them into positions 10 and 11 (audio controls) of the clockspring connector:
Next I spliced pins 1 and 6 from the pigtail (lighting ground and power) into the existing harness:
The two wires added at position 10 and 11 on the clockspring connector will then need to be joined to the other 2 wires left on the pigtail for the audio controls (pins 5 and 7):
Tape everything back up into a complete harness:
And install back into the steering wheel:
And you are finished:
My aftermarket audio unit comes in next week, so once I install that I will report back on whether the controls all program properly. I haven't bothered checking to see if the audio control wiring is all in place from the backside of the clockspring to the radio. From what I understand it is all there already, but if not then these instructions are to be continued.
C2208 (RH control plug being added with the pigtail kit):
C218B (clockspring connector):
Hope this helps someone out there. Sorry for the long post.