crazykn, on 02 November 2009 - 07:41 AM, said:
Crazykn, yes, I remember you did this project a while back. Pretty cool!

In my case, I had a stock Volvo changer, and wanted to keep it functional when I get an iPod (all I have right now is the Blackberry). I got the USA SPEC device for the future iPod, but at least I could test it out using the Blackberry.
The biggest problem is the proprietary Volvo 8 pin mini din connectors. I'm working to locate these "special" connectors.
I've only noticed one small problem. When changing from the CD Changer to the Blackberry, it works perfectly. However, when changing from the Blackberry to the CD changer, I get a little bit of audio from the Blackberry for a few seconds until the CD changer takes back control. For a few seconds (2-3) the audio from the CD changer is slightly distorted until the M-Bus handshaking normalizes. I'm thinking that perhaps I should switch the audio lines as well as the ACC line. I'll be trying that approach on the second prototype.
The easy solution to the problem is to PAUSE the SC-816 before I push the antenna switch - wait 4 seconds, and un-PAUSE the SC-816. In any case, it doesn't bother me with the momentary "confusion" that the HU experiences during the changeover from the USA SPEC device to the CD Changer.
The OEM antenna switch uses the OEM wiring harness, so there is no cutting or splicing needed. I only tapped into the two antenna wires (12V and switched 12V) at the rear left corner of the trunk, and a ring terminal for the ground wire (the relay ground). I'm trying to make this a simple, quick and clean installation when I'm finished.
My ultimate goal is to make this adapter as flexible and versatile as possible. My adapter should be able to use the Blitzsafe or the USA SPEC device - as well as a MP3 player via the AUX ports on the Blitzsafe or the USA SPEC device. You could even use two CD changers if you wanted to.

Even two iPods could be used. Mix and match, if you will.
Cheers! Rabbit