205 Cd Player Wont Play

I have a Peugeot 205XE.
Also have goodmans GCE 7109CD cd/radio player.
Is no ISO connector on car, just a bunch of wires.
I think the thick white wire is the 12v+
and the thick blue wire is the negative.
The thick green is the earth.
When connected as above stereo works until ignition is turned on.

Im assuming all other thin wires are for speakers?

Then stereo has no power.

Any help/advice/links would be appreciated.

Need my music!

Brumm