Dipped Beam Gas Discharge Headlights Dim

[bluey]

Tried a search but couldn't find anything.

My dipped beam lights are more like poor torches than headlights so I guess its either the gas discharge bulbs or the controller units that are at fault not sure which ?. They are OSRAM Zenarc D1S 35W control units in there currently. I have a 2007 D5 185 SE Sport.

Notice the cost of these so hopefully either bulbs or controllers and not both that I need to change. Any recommendations for aftermarket units of decent quality would be appreciated.

I also notice the high voltage label on them so I am guessing you leave the car overnight and let them discharge then ok to change them with battery disconnected ? appreciate your thoughts & advice.

[gmonag]

This is a bit of a thorny subject.

You can fit genuine OEM bulbs for about £125 each or you can buy cheap Chinese-made ones for about £8 per pair.

In my mind there is no contest. Even if the cheaper bulbs only last a fortnight (which is not the case - mine have lasted 2 yrs+), then it is still cheaper to use the Chinese ones. Others worry about the quality/safety/God knows what else. You pays your money and takes your choice..

Swapping them is very easy and you don't need to take the precautions you mentioned. Just turn off the key. Remove the headlights (takes 10 seconds), swap the bulbs and refit the headlights.

[Tannaton]

The bulbs themselves are most likely the problem, it's quite normal for the light output to significantly reduce towards the end of their life.

As has been said new ones from Volvo are expensive and cheap e-bay ones are a risk. However there are several online specialists that will provide branded (Osram, Philips) equivalents at a mid point price. A few have been mentioned on here.