[Jimmy89]

The nearside indicators, the rear, wing mirror and front bulbs all work with the stalk pulled to left hand turn position. If the sidelights are switched on, the front nearside indicator becomes constantly lit with a slight flashing and the relay clicking sound is rapid. Turn the sidelights off and the indicator works normally.
Back in the day, (old school mechanic) I would have gone for the earthing of the light connections but, having taken the whole front light assembly out to inspect the wiring, there are no obvious earthing issues. It's all very modular now.
I'm not even sure there is a conventional relay to operate the indicators. I certainly can't find it. The clicking sound of a relay emanates from the instrument cluster and, having pulled the dash panel to look, it appears to be just a sound generator for driver information. I think we might be into circuit board territory but I don't know. Any ideas would be welcome, thanks.

[Rolebama]

I agree it sounds like an earth issue, but from my experience, not necessarily the on the unit affected. I would check all your light units.
FWIW; A lot of manufacturers no longer use indicator units. They use one 'timer' unit which controls indicators, intermittent wipers and anything else that needs an intermittent power supply.

[Jimmy89]

@Rolebama Thanks, that's interesting about a combined timer unit, I'll try to locate it to check the connector block. It's a bit of a fag having to reveal all the earth points on the separate units, wing mirror lights included, but I take the point. Thanks for your reply, James. 👍 Quote - "It was all so simple once"