... sigh ... sorry to bring this up again, the blinkers have stopped working again but the hazards are working ok. Had a quick look at a wiring diagram and it appears the turn signal flasher relay and the hazard flasher relay operate independently of each other, but you can trust me when I tell you I'm no expert.
Does anyone know if this is this case? If so, should I persevere with troubleshooting/replacing the turn signal flasher relay? If not, any other ideas what it might be, possibly the steering column lever switch?
Thanks again for your help.