Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

Hi folks,
The radio in my 96 Corsa (for which I have the code) is permanently saying 'safe'. Ive tried holding AS while turning the ignition on etc but I dont get a beep and cant input the code.
Ive tried this radio in my Zafira and it works fine using the AS button to input the code but as soon as I put it back in the Corsa, it just displays 'safe' again.
Im guessing its got to be something wrong with the Corsa wiring but so far ive only had a look at the stereo plug and that looks OK. Any ideas gratefully received.

Take to vaux imo should sort it in 5 mins

Finally cracked it!!!!!

It only works when the ignition is on th only worked for me when the ignition is at the position to turn the engine over.
So I unplugged the HT lead, turned it over, pressed AS, pressed radio on and it allowed for the code input.

Hope this helps someone else as I trawled the net and couldnt find a solution.