The possible causes are short circuit, flash relay failure, excessive contact clearance and other factors.
Open the flash relay cover and check whether the coil and resistance are intact. If the resistance is heated and the contact cannot be closed, press the movable contact; At this time, if the turn signal lamp is on, it indicates that the relay is faulty. When the contact clearance is too large, it shall be adjusted.
If the steering light does not light up when the movable contact is pressed and the contact is closed, the contact can be short circuited with a screwdriver. If the light is on at this time, it indicates that the contact is oxidized; If the steering light is not on, the steering switch may be faulty. Use a screwdriver to connect the live wire of the steering switch and the left and right light wire terminals respectively. If the light is on, it indicates that the steering switch is faulty and should be removed for maintenance or replacement.