Standard Garmin 2610 to BMW Nav II Cable

[foolsparadise]

I need some help from the Garmin experts. I am hooking up a standard Garmin 2610 to the BMW cable and will be cutting off the second connector used on the Navigator III. I have metered out all the connections to make sure it will work. But I have one unknown, Pin 3= "SPEED", based on the only pinout connection drawing I could find. Anybody know how that signal is used in the BMW (2007 Comm Voice II). There is also an unused connection call "REVERSE", any idea what that one is? Just curious on that one.

I have also attached a PDF with the pinouts for all the connectors. I would appreciate hearing if anyone can see any errors. I can then post it for reference if anyone ever needs it.

THANKS...

[jzeiler]

The only one's you need are the speaker +/- and 12 V/ Ground. The speed and reverse were used for dead reckoning on some of the older models (2650).