Muting signal for car stereo

Hi everyone,

I recently replaced my car stereo, and noticed it has a connection on the back for 'muting' the stereo when it is connected to a mobile phone (and there is a call). I assume it is a 'standard' system. does anyone know what kind of signal is needed to mute the stereo? By this I mean does it need +12v, GND, or a digital signal?

If it's a digital signal, does anyone know of a simple way for me to produce the muting signal? I have searched on the ned, but can't find any relevant information.

The stereo is a JVC KD-SX991R.

Any help appreciated.

Try tying the line to ground via a 10k resistor, if that doesn't work try tying it to +12V via the same 10k. One should work.

Hi sceadwian,

I thought that too, but i tried connecting it to gnd and +12v. Neither had any effect on the volume of the stereo.

Anyone else have any ideas??