Rear left running light doesn't work
For about a week now my rear driver side running light thats on the same bulb as the stop light works intermediately. Its the double filament bulb and the stop light will work, but not the running light. Sometimes the running light will work it seems but most of the time it will not. Where should i start looking from problems? I replaced the bulb and the old ones connector was broke and there was like black/brownish looking grease inside the connector where the bulb goes, my dad said it was corrosion. What could be my problem and where can i start?