Are the bulbs new and did they come as a pair?
Hi the bulbs are the same make and part number but the lights were bought at different times and are made in different years.
But this is not the problem, i swaped them over left to right and there is still the problem on the right hand light.
So by elimination it's either the earth or the wire not carryring enough current.
On my TIS cd the wires for normal lights is 0.5MM but for HID it's 1.0MM.
When you think about it the wire from the fusebox to the left light is about 12" but to the right is about 10-12 foot.
So tomorrow night i'l give them both a try.
I was going to suggest that the bulbs ideally need to be paired, as they do go 'off' and discolour, but your experiment proves this is not the problem. I can't help you at all with the electrics sorry, you're talking to the wrong man.
Thanks anyway, i'll give my other ideas a try and keep you posted, it may help someone else in the future.