w124 Radio Install and Fader Bypass

[rrgrassi]

I am trying to install a new JVC head unit in my 91 w124.. I am also by passing the factory fader.

I do have some questions. Do the speakers share a common ground? I have identified and temporarily connected the positive out put from the head unit to the factory dash and rear speakers, but not the negative side, and all the speakers work, except I have not tested the door subs.

I do want the door subs to work. If not I will go a different route.

So, here are the questions...where to the colored wires connect? They came out of the fader.

Also, what does this gray bundle control?

[rrgrassi]

I got it figured out. Used the data cable for rears and sub power signal.