Audio Muting in 1998 S500
I am looking for details on how to mute the audio system in my 1998 S500. The vehicle is equipped with the integrated cell phone system. I want to connect the audio output of my Laptop PC to the input of the audio system where the cell phone connects and mute the radio, CD, etc. audio when output comes from the laptop. My specific questions include;
1. Do I need a specific separate control signal such as a ground to cause the muting?
2. Will just the presence of the laptop audio signal mute the radio if it is input through the cell phone input?
3 Which plug at the back of the radio head unit do I tap into for muting and which specific wire? Also, which wire for the audio input from the laptop.
4. What about isolation from the cell phone output?
Any help in this regard would be greatly appreciated.