Left headlight problem sounds like first symptom of gearbox failure.
C5s have different logic depending on year and whether equipped with
twilight control. Post the year of the car and hope someone here has a
troubleshooting chart for that model.

HamOp wrote:
> When I turn the headlights off , the left headlight makes a grinding
> sound for like 8 seconds after its down ? Also when i put my fog
> lights on my headlights pop up? This all started at the same time.
> Thanks
> Bob
>