W208 Front Fog Lights

[DarrenG]

Starting to think it's time I off-load this one as it's a new issue every other week it would seem!

Got the bulb failure warning in the instrument panel for front fogs. Went out and bought Bosch replacement bulbs x2 and installed. Warning still present and fogs don't illuminate.

Checked Front Fog Light fuse, OK but replaced anyway, no change.

It's in for a service and MoT tomorrow, is this an MoT failure?

 

[Nibbo]

I am sure this will be a failure. Basically; if it fitted to the vehicle it must be in working order.

 

[DarrenG]

I thought so too but looking into it apparently not. It's not a mandatory light and as such front fogs, factory fitter or otherwise are not tested.

MOT Testers Manual

 

[Howard]

Darren , if the fuse is ok , and the bulbs are new and they still don't illuminate it can only be a break in the wiring ...

Are the rubber connectors on the back of the bulbs connected properly ? they are fiddley to get on .... try putting one on a bulb that isn't seated in the housing and wiggling it to see if the bulb lights ...

I had a fog like that on mine , seating the connector firmly did it for me ...

Failing that , start tracing the wiring and look for continuity ....

 

[DarrenG]

The plug is fine, no issue fitting it and both lamps are out. Apart from the short pigtail from the lamp body it then joins a massive cable bundle near the headlamps and disappears towards the firewall. I'm gonna leave it for the garage, if it isn't an MoT failure then they can stay busted as they're a waste of space anyway in fog!

 

[Howard]

Checked the switch unit on the dashboard for continuity ? that power actually leaves the switch to the fogs ?

 

[DarrenG]

Is the light switch easily extracted?

 

[ollieclk]

I thought so too but looking into it apparently not. It's not a mandatory light and as such front fogs, factory fitter or otherwise are not tested.

MOT Testers Manual

It might not be an mot failure but you will breach the contruction and use act as any light fitted to a vehicle must work.

 

[DarrenG]

I think I can live with that, as I don't plan on using them my conscience is clear!

 

[BlackC55]

It is not tested on MOT's.

check the connectors as it is very common for them to corrode.

 

[DarrenG]

Cheers, too late for me to check now but I'll be sure to look at that after I get it back and a liberal dose of WD40.