I have a pioneer super tuner3d it has a mute wire where does it hook up to

This is directly from the installation manual from pioneer website for model DEH-P6600

(Yellow/black
If you use a cellular telephone, connect it via the
Audio Mute lead on the cellular telephone. If not,
keep the Audio Mute lead free of any connections.)

Basically, you don't hook it up unles you have a cellular telephone in your vehicle, not a personal cell phone.