i drive a 1989 300E. recently this started that every time i turn my lights on, the left turn signals will stay on, not flash, just stay on. and i have no idea what is causing this, i have replaced just about every light bulb, and it still does it, if anyone knows what could cause this please respond. thank you

maybe something electrical that bulb receives or maybe that the entire unit is bad...

I too have a 1989 300E and I am having a similar problem.

I recently changed the front blinker bulbs. Since, signaling left or right will cause both sides to flash as if depressing the Hazard switch. Blinkers were fine prior with the exception of the front right blinker was not functioning.

Tried changing out with even newer bulbs but have same result.

Have you had any success with it?