Manual Transaxel on '95 200SX SER

[Russell]

I'm in the process of draining and filling the transmission fluid w/ Amsoil
synthetic.  However, I've got a few questions:
    First, I'm using the Haynes manual, and it just says to remove the
"speedometer drive pinion" to fill it up.  I think my year/model of car must
be different.  I just added fluid until no more would go in at the second
major plug.
    I can only see two areas, listed below, that I could possibly add more
fluid into, which one is the right one, and how do you tell when you've got
plenty in there?

1) on the front of the transaxel facing the front bumper there's some kind of
electrical sensor going in a hole, secured w/ a phillips screw
2) on top of the transaxel is a hose coming off that's just open ended (what's
this hose for anyway?)

Thx,
Russell
'95 200SX SER