EDIT: The project was a SUCCESS! The following pages are a step by step of the process(es) used to figure everything out. I opted not to use the factory extend switch (although it could easily be wired up and made to work). I used an aftermarket telescope/extend switch instead.
I've written a How-To for this mod. It's located here: Wiring 2008+ Power Fold/Telescope Mirrors into 1999-2007 SD Trucks - The OEM way
Please use this thread to continue discussion on the OEM switch and operation here, as the How-To write-up doesn't allow replies.
I have had my eye on the 08+ power fold/telescoping mirrors for a while now. I finally picked up a set of 2011 OEM power fold mirrors a couple weeks ago. Now begins my quest to get them fully functional AND still keep things as close to factory as possible.
First off, the 2008+ trucks use two switches to control the mirrors - The first is a round power mirror control switch that included the power fold in it. For power extending, it has another rectangular switch mounted on the same bezel. My goal is to use both of those switches in my 2005 to get the factory look and function with my new mirrors.
To start, my 05 has the same switch/lock/mirror bezel that the 99-05 trucks had, and therefore had the square shaped mirror switch. The 2006-2007 trucks use a slightly different switch and bezel - Their mirror switch is VERY close to the 2008+ mirror switch and is the same size. The only difference (aside from wiring harness) is that the 2008+ switch mounts with the plug towards the front, whereas the 2006-07 switch mounts with the plug towards the rear. Aside from a very small notch required to mount the 2008 switch in backwards, it's virtually a direct drop in.
Pics for reference, 99-05 is on the left, 06-07 is on the right:
Here is a reference pic for the 2008-12 switch:
(Note the plug is actually 180* different than the 06-07 switch. I believe this is one of the reasons that people always report their switch controls are reversed after install/wiring 2008+ mirrors)
Here's one more; showing the 08+ switch and power extend button:
So, the basic plan is to install an 08+ adjustment switch into the 06-07 bezel that I bought and wire it up. The next is to install the power extend button in my dash. The previous owner had a toggle switch drilled into the lower dash to the left of the wheel, so I'm just going to cut that hole to fit the power extend switch and mount it there.
Obviously the wiring is another matter. Through my searches here, I've found the wiring diagrams/color codes for both my '05's factory wiring and also for the replacement mirrors. The switches don't look that tough - I'll figure that out and report back.
This process won't be an overnight thing, but over the next few weeks, I'll be updating to include new pics and overall progress. In the end, it should look as though it was completely factory and should function as such.