I’m afraid that the dog’s breakfast that is theTF workshop manual isn’t much help other than to say it’s the hazard flasher that also operates the indicators, it’s somewhere in the vicinity of the interior fuse box, in fact what it has told me is that there are 10 relays on the fuse board… of interest are relay #5 operates the L/H indicators and relay #7 operates the R/H indicators.
Check the hazard switch it could be your problem.
Check under bonnet fuse #4.
Check fusible links #6 & #5
Check interior fuse #23
That’s all there is on the subject, sorry I can’t be of more help.
As I’ve mentioned elsewhere the manual was written not by someone with mechanical aptitude…. No it was written by someone with mechanical ineptitude!
Still now that phone books are a thing of the past, the police could use the manual as a substitute for interrogation purposes ( belting the living shit outta suspects with the phone book leaves no bruises and doesn’t hurt your hands.)