Thanks for your help - much appreciated - but hold fire! I think I've traced the fault (the headlights are on all the time when ignition is on and engine won't stop if headlight switch is on!) to the wrong ignition switch - at least, the wires don't match the colour codes in the Haynes manual. My next question - has anyone got a barrel and key for an '83 GTL?? I'll post this seperately.