My indicators seem to be very dim, all of them! I have just had someone shouting at me for not indicating, I have no idea how long they have been like this. I don't know what to be looking for, one I could understand but not all.
It's no 12. If it's already replaced I suspect the wiring having too much resistance. I had the same. A new relay didn't solve it, but I fitted LEDs and am now going to look for an adjustable one which accepts LEDs. https://clubgti.com/forums/index.php?threads/indicators-blinking-slow.293816/