blazej01

My passenger side headlight sometimes turns on and sometimes it does no. What do you guys think it could be ballast or bulb?

richard-tx

If it is the 2003, I would change the bulbs and go from there.

TSHong

+1, most likely bulbs. When you turn the light on, does the light spark once but wont light? If so then it's definitely the bulb.

blazej01

It is 08 s8. It works sometimes and then when I go to turn it again it is off.

Brozee

Start with the bulbs as the ballast is $$$. You can find bulbs, equal to OEM Phillips/Osram for under $50 for a set. This way you have new bulbs as you will need new ones anyway. Yours are probably turning a bit blue at this point so it doesn't hurt replacing them now and starting with the bulbs. I just replaced my headlight bulbs in my 2005 A8, original bulbs never went out, just had slightly reduced distance and turned a bit less white.

Only issue I've had with my headlights in the past was the driver side auto leveler would sometimes be dipped. Random and fluky, hasn't happened lately though.

richard-tx

I would put a pair of Nightbreakers in. They are old enough to need replacing anyway. I would not mess with cheap bulbs. They just don't last.

Brozee

+1 those are great bulbs. Wish I went with those instead of the stock OEM Sylvania D2S I bought. Still work great though

jlbell

Easiest way to tell if it is the ballast or bulb. Put your ear to the suspect headlight and have someone switch on the light. If it is the ballast (light doesn't turn on) you won't hear a buzzing noise simple as that. This is because a working ballast make a slight buzzing when it is operational.