This morning, when I was driving my car from my apartment building, I noticed that the left turn signal was flashing much faster than before.
Then I noticed that the left rear turn signal was not working.
So I bought a new PY21W bulb in the store, replaced it in the left rear light, but unfortunately it did not help...
Since replacing the bulb did not help, I would like to ask for advice on what is the possible cause?



Here is a video showing how to replace this bulb: