My bike's turn signals supposed to be on as default while both riding and parking. I don't know how that thing is called in English so I put a promotional photo. as you can see both turn signals are on while riding and blinkers work via turning off and on in a constant rate. Recently one of the signal's decided to not work that way. Light bulb is fine and if I try to signal, it will but it does not stay on as I ride. I couldn't find any relevant information in the service manual either. What may be the cause of the problem? The following is the electrical diagram of an older model which supposed to have the same turn light property.
The problem was (in this case) the lightbulb. The lightbulbs contain 2 sets of filaments. One is for blinking and other is to stay on while the signal is not blinking. This is probably because they didn't want to reduce the lifespan of the blinking part as it is crucial. As paulster2 mentioned they were working intermittently and that there was no visible break in the filaments. My, for the lack of a better word, the conclusion is merely a result of swapping left and right bulbs.