When looking for videos.
IIRC
97-98 central axle disconnect.
Switch positions
2wd, A4wd, 4wd, 4lo
99-02
No disconnect on axle.
Switch positions
A4wd, 4wd, 4lo
This is the years people do the brown wire mod on.
2003-current I think
Integrated wheel ends (“iwe”)
Switch position
2wd, A4wd, 4wd...