[P156KWJ]

As a side note I was going to suggest the bulb holders themselves are in poor condition until you said the dash light doesn't appear. On mine both fogs didn't work when I bought it, one of two bulbs was blown but also both gold translucent coloured bulb holders were knackered partly due to the rubber O ring failing over time and letting water in which took care of eating away at the conductors. Strangely on Skandix the correct bulb holders are listed as not being compatible with S and V40s but they are. They are fitted to XC90s amongst other models. I replaced them and they are fine now.

Digressed slightly there but anyone else who has front fog problems may find this helps.