n4

2002 A4 Quattro 1.8T, halogen beams (non-HID)

Hi all. I've searched the forums and the technical resources but haven't come across anything conclusive in regards to this problem. Wondering if we can come up with a list of alternative problems/solutions in a single thread as sort of a FAQ on headlights?? Probably being optimistic on this due to all the different year/models but thought I'd try.

My driver's side low beam is out. I got a new H7 bulb but the low beam still doesn't work. Under the technical resources there is an article on cleaning the switch contacts behind the steering wheel but it is for the previous generation vehicle. I also found a lot of people seemed to have the same problem and posted in the forum but those threads left the problem unresolved.

Anybody who has had this problem and got it fixed, do a brotha a favor and please post your solution(s) along with year/model.

Mucho appreciated.
n4

Ming02

w/ the ballast and/or bulb contacts. I want to take the headlights apart and clean/inspect the contacts as well as put some dialectric grease on the connections to avoid future problems.

I'd imagine that the Halogen set-up is much simpler - I'd focus on checking the connections at the bulb. The switch in the cabin would be less suspect to me because it doesn't see the weather. But problems can arise if the switch is not properly desinged to handle the current draw of the bulbs. This can lead to corrosion/arcing of the contacts in the switch. Then cleaning and/or replacing them is necessary. The only fix for this besides a heavier switch is to set up a seperate circuit with a relay. The light switch will trip the relay, which will draw it's power from a more reliable source. I've done something similar to this on my 914 to bypass the ignition switch so that the starter solenoid gets more current. Works like a champ.

Michellelle

Once my dummy light showed that it dipped on the display, the headlight still worked, but sometimes would flicker. Took it to Audi and they couldnt verify my concerns. So this is what they stated on my invoice: could not verify customer concern. Called Steve Shupe and was instructed to swap ignitor modules from driver side headlight to passenger side headlight. performed this unflanged battery removed both headlights and road tested after this extensively. Did find that passenger side headlight still flickered and found bulb in headlight faulty. Replaced bulb and had to R&R headlight a 2nd time unflanged battery a second time restored power a second time. BAsically, they changed the gas bulb. Hope this helps. Oh yes, I have an 04 A4 xenon. Part #N-105-661-03 Gas Bulb. I think they are $$

diagnosticator1

The B6 lighting circuits are switched by the Central Electric Control Module, not the user switches directly. The headlight switch, only causes the solid state transister relay high current switch inside the CECM, to "shift state", that is, to either be in the very low resistance or "closed" switch, lights ON state, or at a very high resistance "open" switch OFF state, headlights turned off.
The relay mod you described for earlier Audis, is actually now used OEM by the CECM solid state high current transister switching provided. The steering columb/dash lighting switches, do not carry full lamp current loads, only very small currents needed to effect the transister switches inside the CECM.