Thanks Aloysius,
I have fitted the unit and it is getting power. when the ignition is in the 'off' position the red 'Code' LED flashes. When I turn the ignition on and turn the on/volume knob a single '-' appears just to the right of the centre of the LCD display, and it illuminates (a bit).
Leaving the ignition in the 'on position and the head unit turned on, eventually two more '-' hyphens appear on the LCD screen. However I do not seem to be able to enter the code. I isn't clear whether the LCD screen is broken, or if this is normal behaviour for a unit which is IMMO coded to another car. I have pressed the up/down and left/right buttons as well as all of the preset radio station buttons to see if the hyphens go away - the logic being that if the LCD screen has failed and it is accepting inputs then if I am cycling through numbers 0-9 then a '1' for example would not include a horizontal dash.
The unit was removed from a P10 primera and I have fitted it to my N15 almera, the wiring harnesses are the same, though I have needed to use an adaptor for the aerial input to change it from the 'needle type' to the 'popper type'
Thanks
Stanky