Radio Aux-in mod - need help!

[dsilbert]

I read the following post from bobbch:
http://www.volvoforums.org.uk/showthread.php?t=106676

I’m interested in adding the aux-in to my 850's SC-810 radio. But on his Oct 9th, 2010, 12:13 post he didn't include where to connect the other end of the cable, from RUN-DET. He wrote: "Also, we need a SHORT length (of wire), one end onto the RUN DET and the other end onto the pin labelled." Labelled what, which pin?

DOES ANYONE KNOW WHICH PIN TO CONNECT THE OTHER END OF THE WIRE TO FROM THE RUN-DET? The reason this is done is to trick to radio into thinking there is a cassette inserted into the player. My player is trashed and will not load a cassette.

Less important, but interested if anyone knows why he suggests that we solder onto main board as opposed to soldering onto riser board, then snapping it back in. Also, can we ground the Aux-in cable to the A-GND pin on the board?

If you know, please advise. Thanks!
dsilbert
dsilbert@tampabay.rr.com