Turn Signal

Firstly I would check the wiring, is it taut or showing damage or loose connection. Check at bulb holder too, is earth clean and connectors too, clean and spray with wd40.
Can't be much really.

 

Easy, just make left turns....

 

@Eric27 Yes i would try for taut wiring. Also check the bulb holder as i have seen them to lose contact. What i do is dismantle the centre bulb holder and stretch the spring in there just to give a better hold.