24 small ones plus two larger wedge bulbs but they mainly are for the side indicators, tire pressure light, seatbelt light etc. The bulbs are not expensive and are easy to change once everything is apart but I was warning you to be prepared if you are going to take everything apart. That is puzzling the left side is silent, I can't see that a bulb would be the culprit. Like I said there are exactly 3 bulbs behind the turn signals. Maybe check the service manual or check the Mercedes forums to see what the problem could be because I have no idea.