I-90 heading East tonight, 8:00PM, infrared return says it's 41 degrees with a helpful snowflake. I'm going 75 behind a black 993 non-turbo.<p>We pass the three Rockford exits. No traffic. A couple of trucks. We whiz by.<p>I enter an 80 degree turn with a crappy shoulder and a negative bank. The Porsche hits the end of the turn, I'm 30% of the way through the turn, preapex, and both headlights fail at the same time... corner lamps remain still lit. Shocked, I move onto the outside of the turn shoulder (illegal in Germany, but probably legal in the U.S.)... both headlights are out. I walk around, wondering if I should grab the StarTAC and dial that Audi Assistance number I've used so many times that it's one of my 99 stored numbers. Suddenly, the headlights come back to life, both at the same time just like they failed. I keep driving. Passing the Huntley factory shops. Boom, no lights. I pull over. Wait. Lights come back. I pass under Barrington Rd., my V1 beeps, I unplug it because the tollbooth near Rolling Meadows lets out tons of radar. I keep going. Nearing Arlington Heights Road. I get off, pay the toll, headlights fail. Thank God I'm near home. I wait in the Guitar Center parking lot, the headlights relight themselves after the longest failure interval yet -- almost 6 minutes by my watch. That could be 8 miles without headlights for some of us with more spirited A4 driving styles (!). My A4 limps home with bad lighting electricals. The one thing I haven't screwed with on this car, and it fails three different times between WIS12/18 and Arlington Heights Rd. Amazing.<p>I wanted to warn everyone. I plan on going to a dealer to get this fixed under warranty, any suggestions? Audi Exchange? Laurel? Loeber?<p>Thanks for listening,<br>Cameron (sometimes blind 97A4TQ)

My old VW GTI had wiring problems, resulting in a new wiring harness in<br>the dash...but never on an A4 have I heard of this. The only electrical<br>issues I recall has been related to the heated mirrors and sunroof<br>switches/relays.<p>Steve S.<br>97 2.8QM

Cameron, sorry to hear about this, but I suspect the steering column lighting switch/stalk. If you turn on the lights, then jiggle the stalk, do the lights flash? If so, the switch is going. <p>Had a similar problem with the hi/lo beam switch on an old 911; the lights refused to stay on low beam. Had to hold switch/stalk in the low beam position.<p>Another thought is (possibly) a bad relay; think that there is a relay that controls the power to the headlights. Unfortunately, I think all the relays are difficult to get at, or I'd suggest giveing them a push to make sure they're fully seated.<p>By the way, do you have stock headlight bulbs? If you put in hi-power, they might have prematurely fried the relay or switch.<p>You're still under warranty (right?); bring it to the dealer FAST! Good luck.

nt<br>

Just something for you to think about. I had (still have) a similar problem with my '88 Mustang. When the fog lights are turned on (in addition to the headlights), the headlights will periodically go out for about 30 seconds, then come back on. This will continue to happen as long as the foglights are on. There was a TSB on this for (as I recall) insufficient gauge wiring in the headlamp switch which when overburdened would trip a breaker, before resetting. <p>On another note, this is not the first time that you've mentioned an infrared return. Unless I am missing something here, the temperature probe in my car is in front of the radiator and appears to be a standard thermocouple - with no direct "access" to the street below. Are you sure about this?

The A4 on the other hand I would definitely have fixed. Probably something with the switch or relay.<p>Steve

... and on the 1996A42.8RQ we imported in 1996 (and converted to US spec). Appears there is a (focal independent?) lens relay under the car, and it tests in positive equivalent power (volts) when you put a photo guage under it. I used a Kodak R100-50 sensor, and it gave the green light on infrared with yellows across the board in the other spectral fields. Maybe the A4 no longer uses these returns. If so, it's probably because the lens is vulnerable to impact damage (should the rare condition arise that your car gets "speared" from below). The lens attitude points the majority of power 30 degrees to 40 degrees forward. I've had it fail, and the service guys couldn't get the newer unit (which simply guages ambient heat level). My only reservation is that it guages air temperature and not pavement temperature. If a replacement were needed, however, I'd go to the less vulnerable sensor.<p>Easy way to test which sensor your car has:<p>If the temperature often drops from 118F to 92F when you hit pavement in shadows, or more importantly from 38F to 31F when you cross bridges, you probably have the old sensor.<p>Cameron (with two strange A4's, I guess)