[K800i] Fastport to mini jack 2,5mm (3 pins). How to?

[juzeff]

I've got cable from my stereo headset (2 speakers+mic) http://img9.imagevenue.com/img.php?image=62442_P7050269_122_1005lo.jpg
Cable has 5 wires from pins: 2, 3, 4, 5, and 6 (http://pinouts.ru/CellularPhones-P-W/se_k750i_pinout.shtml). Pins 8 and 9 are already connected. I want to connect thiscable to mini jack 2,5mm. I need it for my car handsfree set (1 speaker+mic). I've got a special connector for Siemens C55 that was in the box of handsfree set. It has only 3pins mini jack 2,5mm http://img139.imagevenue.com/img.php?image=62438_P7050267_122_1132lo.jpg (on the photo there are the Siemens connector and the seperate mini jack I need to use to connect it to the Fastort). I connected wires from pins 3 and 4 (mic-, mic+) to mini jack (2 pins) and the mic is working fine. But I have a problem how to connect the speaker? In mini jack only one pin left and I've got 3 cables (speaker left, speaker right and headphones common) from Fastposrt. I've tried to connect speaker left cable to 3rd pin in mini jack, but it didn't worked. How to connect wires to mini jack?

[Conrad van Dyk]

I know this is probably to late to help... but it doesn't seem as if you ever got an answer to your question.

The speaker-earth (headphones common) should be connected to PIN 2.  I am busy doing a similar adaption to yours for the headset in my motorbike helmet.