Thanks all, it turns out it is part of an ongoing issue I have had with the ignition switch. My last call for help was around the engine just dying, which was fixed in the same way, by a bit of a jiggle behind the switch. I really must pull it out and see whats going on, but here in Australia it's just coming into peak Morganeering weather, and I'd rather be driving than tinkering. No doubt it will let me down far from home sometime, and then I'll leap into action. I did acquire a new ignition switch when I bought her, but haven't got a roundtuit

Thanks for all your help and constructive suggestions. I love this forum.