This has been a recurring safety issue problem! The front turn signals repeatedly have indicated on etiher side that the bulb is burned out and hence do not light up nor flash when this occurs. Some folks chalk this up to it is normal for bulbs to burn out so I have been replacing them when this happens. But, a new bulb doesnt always work! It gets to be a game of try this bulb and then that bulb and then sometimes nothing works and I plug the turn signal harness back in and maybe a few days later it starts to work so it is more than a bulb issue and a significant safety issue if folks assume that the turn signal is performing correctly and the oncoming cars dont see any sign that I'm planning on turning. I can put in a new bulb and try adjusting the bulb in its seated position and grab the wires and jiggle to see if there is a short or bad conection and nothing changes the fact that the new bulb is not working. Also the bulbs that arent working appear to be in good working order when looking at the 2 filaments
NHTSA ODI 11569752