rexnanet

Hi everyone,

I bought a used w176 and after a few weeks I started noticing a humming noise when i turned the car off at night.
I suspected something related to the fiel pump no having enough voltage due to all the lights being on.

​​​​​​But one time I thought about testing the fog lights during a trip and the noise appeared. So the noise is related to the fog light circuit.
​​​​​​
Now I've done a few more tests and noticed that:
- the humming is not always present as soon as I turn the fog, sometimes takes a few seconds to start (random between 0 and 60 seconds)
- the left lamp outputs less light than the right one. This is with or without the sound being emmited.
- I can't pinpoint the sound origin. But seems to be around the left lamp ( the one that outputs less light)

Does anyone know where the relay for the fog lights is located? Are there two of them?
The sound could be from driving the relay with a high frequency PWM...

I'll try to make a video showing it.

Thanks in advance.