Radio harness connection help please

[Retro Pedro]

Can anybody help me get to grips with the correct wiring to the radio.
The car is a Fiat Doblo 05 reg and the radio is an old school Panasonic CQ-RDP-383N.
The online radio manual indicates:
A7 Red - power lead ACC or IGN
A8 Black - ground
A5 Blue/White strip - Motor Antanna
A4 Yellow - battery ISA

I got the multimeter out to try and see what was what with the loom and came up with the following:

Blank ------ Purple/Black - no reading with and without ignition switched on

White - 11 volt without ignition on - 4.5 volt with ignitiion on --------Green/Orange - 12 volt without ignition so must be main live

Blank ----- Yellow - no reading with and without ignition switched on


BLACK - no reading with and without ignition switched on (I've assumed this is the earth) ------- Red/Black - 12 volt with Ignition switch on - nothing with ignition off (reckon this is the IGN live)

I reckon that the connections I need to the radio are:
Green/Orange: constant live
Red/Black: Ignition live
Black: Earth

What bothers me is the White wire - is that the Canbus connection if required.
Read somewhere that if this motor is Canbus, I need to put a gizmo in there or else it will constantly drain the battery.

Any info will be gratefully received

[Wilberforce]

I'd suggest asking on a Fiat forum perhaps Pete.
I say that because I thought pretty much all European car makers were running ISO standard by 2005, and white is a speaker wire under that convention. As is purple/black for that matter.

I'd also be interested to know what happens to the wires when you turn on the ignition and then the lights as one is likely to control display illumination

[Retro Pedro]