bruce_hyman

well, i didnt think you could wire the car this way, but the recent A4 print ads running in the New York Times, Wall Street Journal and undoubtedly other places show the car with fog and high beams *on*, but low beams and side lights *off*. or that's the way they airbrushed it, i guess.
sorry if this has been snickered at before..

Jretal

gotta play with a relay. search for audifirst. He did a complete write up on which relay to play with... but that was for I believe 96-98 MY A4s... somewhere they changed the design.

2000ImolaS4

This may seem redundant, but there is a reason why the car makers cancel the fogs when the hi-beams are switched on...

The coverage of fogs is wide and short (in length and height).
The coverage of high beams is narrow and long (in distance, but not well controlled in height).

BUT...
Almost all fogs have less candlepower than any high beams. When the high beams are on, they overwhelm the candlepower of the fogs.

Secondly, and more importantly, fogs have lenses that keep the beam pattern short and controlled in both height and distance. This prevents reflections from being splashed back into the driver's eyes (from fog, rain, and snowflakes) - some engineers even claim a reduction in horizontal parallax. Whereas, high beams do the opposite of this; they sacrifice lots of reflective and parallax problems for the benefit of a long distance of view.

Therefore, if you have high beams and fogs on at the same time, the power of the high beams will cancel the benefits of the fogs and you will be left with a lot of light for distance and a low/wide pattern that may cover the curb or shoulder of the road for thirty to fifty feet.

If it's a cosmetic issue that you want to achieve, then I guess you'll achieve that. But bear in mind, you'll be drawing more amps from the battery, too.

Just my thoughts.

bruce_hyman

of course, the fog/high beam combo doesnt make a huge degree of sense. AND vehicle codes might make it "illegal". on th '03 A$, you can set a VAG-COM option to allow high, dip and fog lights - which DOES violate US code, which prohibits the three-light-per-side arrangement.
but this was an advertisement, not a reflection of reality!

[tri]liament

just do the independent fog mod.. article is in the tech section