I copied this from Google images, thanks to Alan Brown (Clockwork Orange) and it may help tracing the problem.
it seems all the indicator circuits are fed through the Hazard switch with the red wire being a permanent live from fuse 1 and an ignition position 2 wire which is black and fed from fuse 7. The red wire (permanent live) powers the warning light on the hazard switch and all the hazards when the ignition is off.
From personal experience I would revisit the condition of the hazard switch and the flasher unit and check that there is continuity to earth from the brown wire on the flasher unit connector. I have had problems with poor earths on flasher units but generally the old lucas types which earth through their mounting on a body panel.
Generally, but not always, indicator stalks start to fail with perhaps one side of the indicators not working. My laser was like that.
Hope some of this helps.