I will be using this adapter to install an Alpine changer in my 2000 S40 and need some help with the 12 volt power source connection. Can someone tell me which color wire this car has as the 12 volt power to the stereo. I am having trouble finding the wiring diagram for this stereo. Thanks.

I used this device, but I cannot how I picked up the 12VDC. You may be able to unplug the radio and use a multimeter to find the 12V line. Did the converter come with any helpful instructions?
Thanks,
Craig

I think I can use the multimeter to find the 12v source. However, do you remeber if you just cut the wire going to the radio and spliced the yellow wire from the adapter into that one? or was it done from a different power source.

Thanks for your help.

Its been a few years now. I don't think you cut any wire, you just pick up the 12V source to run the interface box. Any instructions with the adapter?
Thanks,
Craig

The only instructions that came with the adapter say to connect the yellow wire to a constant 12v power source. I don't know where else to get that without splicing the wire that is feeding the head unit.