147 headunit replacement nightmare

I'm installing a sony headunit into my 147 and retaining the steering wheel controls with a connects2 adaptor, and would you believe it works? I thought it was going to be a nightmare, but no, It really does work.... But the bloody radio doesn't, can't get reception, it just keeps scanning. The standard fit unit, contrary to what I've read, had rather good reception. What have I Done? How do I get my radio to work? Is there really a booster hidden away somewhere?

Did you connect the Power Aerial cable? This happend with my 156 until this was connected

sometimes you need an arial adapter for the stereo type & car model...

potential issues include:
*antenna booster wire: labelled as 'AUT ANT' wire on the schematic atop the original headunit, and is wire #5 in the power-ISO plug; should be the BLUE wire (no stripe) on the sony headunit that connects up (confirm in owner's manual)
*antenna lead: is it connected up to the new headunit?!
*tuner settings: first ensure the tuner mode is set to 'DX' (distance) in case the stations are a weak signal; 'LX' (local) only picks up strong signals, DX picks up weaker ones too