Stereo wiring in new Patrol

Hi all,

Mate of mines got a new patrol and it's got the Clarion stereo with the changer control in it.

I want to wire a Bluetooth car kit into it for him.

For a four speaker system it doesn't have enough wires coming out of it unless they'v e commoned the grounds together.

Anyway. Has anyone pulled one out and worked out the wiring?

It's model is PP2371H (Clarion) and it has a part # on the label is 286-9289-18.

I can work it out if I dismantle the unit and access the board, and take a meter to the plug but if I can save some work I will.

Thanks in advance,

Dave