I have a 1988 Mercedes 300e and the problem with it is that my right blinker won't work when I have my lights on at night (when I need them most) but in the day when Im not using them it works perfect
The circuits are perhaps connected by a filament touching another filament. Inspect and replace the affected lightbulbs that share both circuits.Replace them if a problem is found. Referring to your schematic for the electrical system can help you find every place this is also possible. Water entry or nonfactory wiring can also affect any problematic circuit.
Most times this is simply a bad bulb, the bulb is not seated properly or the connection is loose. First try gently whacking the unit from the exterior with the palm of your hand - it may jar the bulb into position. Sounds weird but works!...if unsuccessful - replace the bulb with the proper one. Since the left one works - you might want to switch them with each other as a test.
One more thing.....toggle your RED emergency flasher unit several times. The circuit may run through it as it absolutely does on the 190e. If this is not completely in the off position the blinkers don't work.
Looking for a Used 300-Class in your area?
CarGurus has 203 nationwide 300-Class listings starting at $2,995.
Search Mercedes-Benz 300-Class Questions
Mercedes-Benz 300-Class Experts