Can't tell you exactly what year this mirror is from but its the rear view mirror with homelink. I have the whole mirror pulled apart right now. There are only three wires to the plug like I said. This mirror must be from a car without auto dimming side mirrors.
The brown, blue/white and red wires go to a plug that connects to the circuit board of the mirror. On the same plug, a brown and blue/white come out of the plug and go to the Homelink transmittor.
This mirror has a large flat mounting base with a handsfree mic mounted in it. That may not help identify it but I can not locate any MB part number on the mirror. Maybe its a pre-1997 mirror.
Anyway, it at least sounds like the ground is the brown wire, thats 1/3rd of the way there
Maybe these pics will help
