JasonByeon

Hello guys

I own 2008 3.0TDI audi Q7 4L

I am having an issue with my headlight brightness which is very dim.

lets say HID Headlight requires about 45,000 candela and my i have replaced bulbs (it did happen even before i changed headlight bulbs lots of times)

and one side come out with 12,000 candela and the other side comes out with 7,500 candela.

I was trying to figure it out so hard that why this happens and even the Audi Service Centre couldn't figure excpet they said we need to test all the power roads. (electrcial test)

I've replaced the Alternater recently too.

If anyone had same issues.. please help me to fix my car

Built4Sin

Sounds like the HID Ballast is going out.

Vaslaz

It's very common for ten+ years old vehicle with HID + Lens. I am almost sure that the problem is in dirty lens behind the glass...
Some stores sells even entire projector (reflector + lens) :
Audi Q7 Xenon Headlight OEM HID D1S Ballast Bulb Control Unit Module Projector Reflektor Bowls Change
or
https://www.aliexpress.com/item/FREE...676802272.html

arU4ic

Generally dimness is the ballast, a color shift (toward red/ pink really) is the bulb. Generally. 2008, its about time for both probably, but try bulbs first.

JasonByeon

Well i have put on the D1S HID and isnt the DS series HIDs combined with ballast? Thought the metal box were ballaster for the HID

If the ballast is the problem, do you know whrere to find it out?

JasonByeon

Thanks for comment but ive done it 2years ago already haha

The lens are very clean

JasonByeon

Well i replace bulbs less than 2year everytime

As i mentioned up there isnt the D1S comes with ballast on it?

Built4Sin

Watch this The Ballast is the aluminum box on the underside of your headlight.

JasonByeon

Thank you for help

I will try to replace the ballast