My '04 XC70 left HID bulb is turning off occasionally. It is an intermittent problem and I'm wondering if there is an explanation other than "bad bulb"? I replaced both bulbs a year ago, and found that both ballasts also needed replacement. Fortunately I found OEMs for about 1/3 of the dealership quote. I did buy aftermarket bulbs though, and maybe they are just lesser quality than the originals.

Any thoughts or recommendations for me?

The car has an unusual (maybe not for Volvo ) headlight system. There are places for high-beam bulbs, but they aren't wired in. Instead, the HIDs tilt up, via a servo, when the highbeams are activated. I don't think this solution provides more visibility, but perhaps that is what I have to live with if our heavenly Volvo engineers have deemed this the "way to go".

 

the ones with the "servo" are aftermarket someone has changed the car to HID

 

Interesting. If the HID were added, they used the OEM Valeo ballasts that are located behind the front bumper. Seems odd to me since the kits have much less expensive ballasts and they put them someplace much more accessible! The lights on this car have the standard Volvo housing too. It is a mystery that will remain unsolved. I'm still wondering about the occasional flickering. Any answers out there?