Pugnado

Hey everyone, newbie here, newbie to owning Benz too, just picked up a 2010 c350 and I am having issues with the driver side fog light...

I noticed when the wife came home last night the driver side fog light was off but the passenger side was working.

When she turned the car off, the light then came back on.

I read the manual and tested the fog lights in fog light mode (pulling the switch out one click) and they do work, but the colour of the fog lights is yellow.

Any idea on why the led light works, when you unlock the car, but when you drive it, it doesn't?

Fuse perhaps?

Cheers eh

416mOe

Have the same exact model...
The fog light(s) turn on when turning the steering wheel in the corresponding direction (turning the wheel left will turn on the left fog light) its supposed to slowly fade off when the wheel is back to center.
you will also notice this when signalling.. again the fog light will turn on with the corresponding signal direction.

MB put run of the mill Halogens in the fog lights.. you can choose to replace these with LED or HID(though i dont know how well they will work turning on when turning the wheel because they take time to warm up) if you want a "whiter" light.

Shimee

The auxiliary lights on the W204 are dual purpose; they are cornering lights and fog lights. The cornering function turns on either when the wheel is turned to the left or right or one of the indicators is turned on, up to 15mph I believe.

Replacing the fog lights with HID or LED is not as easy as it would be on most other cars. MB decided to use H7 bulbs in the fog lights that plug into an adapter. There is an aftermarket BMW adapter that fits but it is garbage and does not align the bulb (either HID or LED) correctly, it also doesn't seal the housing properly and will leak. Best way is to cut the stock adapter to accept an HID or LED bulb, but even then you have to center and glue the bulb to the modified adapter otherwise the bulb will be seated in the housing incorrectly.

I've tried both HID and LED bulbs. I don't recommend HID because they take too long to warm up which effectively renders the cornering function useless. I was surprised with LED bulbs because they are plug-n-play and don't require any error canceller. However, it was a bit of work modifying the adapter and gluing the bulb in so that it sits perfectly vertical.

These are the bulbs I'm using: http://www.ebay.com/itm/272513228814

Pugnado

She was making a left turn and the left fog was off. When she pulled in the driveway the left fog was off too. I switched out the bulbs today with new ones (the left bulb was a bit loose from it's metal base plug).

My local benz dealer tried selling me a whole fog light replacement for $270, instead of just a bulb... :/

Gotta say tho, switching the 2 bulbs out took about 5 minutes (6 plastic grill cover torque screws). I have a Chevy TrailBlazer that I must remove the whole grill, drop the headlights, and spend about a half hour to change its headlights.