S40 front fog lights not working

[P156KWJ]

Phase 2 Volvo S40 (2002), has the winter pack so the fog lights are original equipment.

The dash warning light works for the front fogs (as does the rear, and the rear fogs themselves work fine), and having looked at the wiring diagram in the Haynes book, suggests that a likely break would be somewhere between the fog light control module and where the wire splits to reach each individual light. As they have separate earth points I'd discounted this as it seems unlikely both would be poor.

Are there any usual bugbears that cause these to fail, before I start taking everything to bits? And am I right in thinking the module is somewhere that's difficult to access behind the dash?

Thanks in advance

[aldred309uk]

https://www.volvoforums.org.uk/showt...=67584&page=35

Post #345 and #346 may be of use to you.

The relay on the CEM may be the cause of your issue. I had to replace one of the relays for my dipped beam headlight, it was an intermittent fault and I could get the light to work by giving the CEM itself a tap to make the relay switch. Hope this is of use to you!

[P156KWJ]

Originally Posted by aldred309uk

https://www.volvoforums.org.uk/showt...=67584&page=35

Post #345 and #346 may be of use to you.

The relay on the CEM may be the cause of your issue. I had to replace one of the relays for my dipped beam headlight, it was an intermittent fault and I could get the light to work by giving the CEM itself a tap to make the relay switch. Hope this is of use to you!

Thanks very much! That's a lot easier access than I was anticipating. And found those relays from Fujitsu for £1.96, so it's worth buying one just to check.

Will report back soon...

[clarkey1984]

Is it so inconceivable that both bulbs may be blown? it can happen, when I bought my SE both brake light bulbs were blown.

[P156KWJ]

Originally Posted by clarkey1984

Is it so inconceivable that both bulbs may be blown? it can happen, when I bought my SE both brake light bulbs were blown.

I have known it happen once actually, we had a Mercedes at work (bus), where the driver had lost all his headlights, our sparky had every panel out and every fuse, relay, ECU resets, you name it, and it was two bulbs had blown by coincidence at the same time... needless to say he was the subject of much abuse that day!