Be interested to see/read more on this TallPaul
Sure, Pins are:
Pin 1 = MUTE (to radio)
Pin 4 & 5 = SPK in for Factory Radio (comes out on non-iso spec 3rd block
Pin 7 = IGN +12v (from dash)
Pin 8 = LIGHTS +12v (with sidelights, from body computer)
Pin 9 = +12v (from batt)
Pin 10 = GND (from radio)
This is according to some info I was given, although I found that pin 5 was not populated however pin 3 was, and I used pins 3 & 4 for speaker in and it worked fine (I checked the colours at the other end on the radio connector first etc). The first time I tried it thought here was no volume from the radio, but there is an option for PHONE in the radio menu that is off by default and has to be set to on (factory radio manual had the full directions, but it was pretty straightforward). NOTE PIN ASSIGNMENTS ARE FROM REAR OF CONNECTOR! You need to reverse if looking from the front.
I had my parrot 3000 fitted to this connector with no problems, I now have a SonyEricsson HCB-300 as the parrot is dead (insert monty python joke here), however I was not able to source the matching plug and had to bodge something using some fork connectors with one leg cut off and a good dose of tape round the lot.
It's a good way to fit it, as although the volume on the car kit itself still affects output (because you are feeding the radio) you can also turn up/down the car kit volume with the steering wheel controls which are talking to factory radio, useful on the move if the phone is in a pocket and you have a Bluetooth kit.
Picture of my grubby hand and the connector also attached, connector is found hanging behind the console down by the heater vents (best access is side carpet panel on console), although the "T" with the nearest loom
is near the radio, so I removed the drinks holder (just clips out) and pulled the connector up behind the radio to make access easier - it should be easy when you know where it is... which I didn't when I started!
Hope that helps,
EDIT: Picture attachments now working for me, have finally attached picture of connector for reference of those finding the post with search.