There is some mis-information in this thread, so I thought I would add some more....

I did this swap on my 05 FWD FEH on my own, and I now have AVERAGE ECON in the instrument cluster, as well as the AVE. in the navigation radio. The instrument cluster sends the hybrid and mpg info to the nav unit on the MS-CAN bus, where it is converted to Audio Control Protocol (ACP) so the radio can use it. What the instrument cluster displays is coded in its software, so with or without the nav unit, you theoretically could have the AVERAGE ECON display. If you removed a factory NAV system, you would need to have the instrument cluster computer re-programmed to display the AVERAGE ECON. Probably can be done, but Ford might not want to do it.

Physically, you only have to swap one harness. You also need to add the MS-CAN to ACP module, but its wiring is included in the new harness. You would also have to add a harness for the changer under the passenger seat. To add the factory sub-woofer you would have to change out a major harness on the passenger side, which is expensive and time consuming. I didn't do this on mine. Interestingly, the 05-07 nav unit will accept a DVD input, but requires populating connectors with new wires and a software change. I didn't pursue this, either.

I don't know if the same methodology is used on the 08, but a look at the schematics will tell the story....

 

If you go here:
http://www.motorcraftservice.com/vdi...=productdetail

you can get a short-term (72hours) or one month subscription to all the service manuals for a single vehicle/year for really cheap (16.95 for the month subscription and 9.95 for the 72 hour access). The wiring diagrams are part of the service manuals that you have access to.

 

Great link Chuck. Thank you. From what I can tell the harness is there. There may be another harness included with the Nav ACM that plugs into the "Smart Block" in the center console. Should be pretty straight forward. I also found out from that link that our escape was built on my birthday. Maybe a good sign.