2003 C240, left brake light and rear turn signal stopped working. I checked the bulbs, they were ok, put them back in and they started working. The next morning when the car turned on the headlights the warning came on that the brake light wasn't working again. Any suggestions?

 

Oddly enough, this has happened to me and the fix was brand new bulbs fresh from the auto parts store. Otherwise, you can follow the theory that 90% of all electrical bulb problems are related to a faulty ground somewhere and go with that. If it were me, I'd try the bulb route first and go from there if that doesn't fix it. But, if you go somewhere without replacing those bulbs, they are just going to tell you to get new bulbs.