I have just replaced my clarion head unit with a Sony CDX 300 GT. I
have used the PC99-X24 lead with the sony fly lead so that I can use
the steering wheel stalk.

The installation manual mentions about yellow and red wires for the
auxilliary and perm live feed but is a little vague to say the least.
I have left yellow to yellow and red to red.

With the ignition off the cd will eject but the unit will not go on.
With the ignition key turned to acc position the stereo turns on and
functions correctly.

The Sony does not lose memory settings or clock (clock doesnt show
with ignition off)

The old clarion head unit would turn on with ignition off until
economy mode kicked in.

How do I make the sony go on with the ignition off?

Thanks in advance