I ordered the factory nav system on my 08 GT vert. Is there a way to unlock it so that it can be used while driving? I know it's a safety feature, but stopping each time to program an address can be more dangerous than simply doing it while going, especially if you have a passenger who can do it for you!
I'm not sure about on Ford's, but in other brands (like my GMC), it usually only takes a toggle switch on the vss wire.
VSS = Vehicle Speed Sensor, I assume? If you disable that, does the system still work? Or is that only so the system can guess what you're doing if it loses the sat signal in a tunnel or something?
I think you are okay leaving the VSS. I know on my AVIC-D3, it's okay to leave it connected, even when bypassing. I believe the VSS helps the nav place your car on the map correctly.. On the Pioneer AVIC-D3, you're supposed to ground the e-brake wire, while also relocating and grounding the Yellow/black mute wire. I know you are talking factory NAV here, but some of the wiring might be similar. First thing I would do with the factory NAV is pull it out of the dash and see how the wiring looks.. You might also be able to get some help on AVIC411.com.
You may be able to put a switch inline on the vss wire so you can "turn it off" when adding addresses and such, but if it has any type of internal gyro like the pioneer nav units it will not work.