Interesting info but getting back to the original problem ( which has recurred following a good few months of driving around with everything working fine )
I got a useful reply from HIDS4U which I hope may help others
Sounds like you have got a faulty ballast rather than bulb – quite common I am sorry to say.
We have sold many ballasts for the Laguna and we have the later type which is more reliable. They cost 150 pounds inc vat and you would need the D2R type bulb if you decide to buy a bulb also.
I actually would recommend you buy a pair of our upgrade D2R bulbs for only 69.99 plus pp as these are much whiter and better performing than the yellower OEM bulbs.
The links you need are :
ballast: Valeo Ballast for Renualt Laguna - 150 - HID and Xenon lighting kit
OEM bulb (1) D2R Bulb Osram or Philips - 59.99 - HID and Xenon lighting kit
or pair of upgrade bulbs HID Xenon 6000K Upgrade Bulbs (1 pair) for D2S and D2R - 69.99 - HID and Xenon lighting kit
For the fog lights you could convert them to real Xenon using one of our kits and you will be able to fit the kit yourself as wiring wise its simple with only 2 wires to connect to existing wiring using spade connectors provided.
This conversion will transform your fog lights into amazingly bright high performing lights with over 300% more light on the road.
All our kits come with 2 year warranty and our prices include VAT. Postage is only 9.99 using City Link (normally)
The kit you need is HIDS4U Pro - HID Xenon Conversion E4 Certified Ballasts - 209.99 - HID and Xenon lighting kit
Or a more modest upgrade would be a pair of upgarde halogen bulbs H7 Ring Sportz Blue 100W (pair) - 23.99 - HID and Xenon lighting kit
If you need more information please let us know
LED lights Latest HID and Xenon lighting products from HIDS4U Ltd, Leeds UK