help on sat nav sound wiring

[Chris D]

i need a hand on wiring the sound for my sat nav. Trying to fit sony md head unit + all the necessary adaptors for sat nav + steering wheel. I have this question:
on my boost head unit connector i need to figure out which wires i use to get the sound going in the right front speakers when the sat nav speaks. Which wires are they? i was told they are on the white connector CB891-B. But there are three. which two do i want out of pin 2,8 and 9.

After that i gunna have fun passing the cd changer wires through to the back of the car. Is there an easy way of doing this?

cheers