Hello, and sorry to say, you are in for a disappointment. I have a 2004 Expedition, the third Expedition I've owned (1999 and 2001 models). I was shocked to learn that Ford had changed the design from the earlier models so that one *cannot* adjust the temperature of the A/C when in the "Max A/C" setting. The warm air mixing only can only occur when in the normal, non-recirculating mode. I've been frustrated by the dealer and by Ford for stonewallng me on this.
Since I travel on business a lot, I rent a lot of cars, including Fords, and have, so far, found only the Expedition has this 'feature' in the Max A/C mode. I've rented Ford Escapes, Mercurys, Mustangs, etc. and to a one, they all mix warm air in the Max A/C mode. Every vehicle I've owned since 1966 works as one would want, but not my 2004 Expedition!
I think it is a defective design. For example, to control the cabin temerature you have to have the A/C in the normal, not Max mode. Well, I ran some tests and found that here, in Arizona, when the outside air temperature is above 110°, which is often, the cabin temp goes too high. Then, if you switch to "Max A/C", you freeze yourself out! So it doesn't work!
Next, this past summer, driving through western Idaho, I spent 8 hours driving through forest fire smoke and couldn't switch off the outside air without going to "Max A/C". See above remarks about how you freeze when this is done. So.....
Well, I am confident you can tell from this overly-long message I'm still steamed about this! The Expedition is at the dealer again this very day and I'm giving them one last chance for them and Ford to make it right.
signed---Steamed in Arizona