vwduud

Of the 2 non-solid areas on the windshield, near the rearview mirror, what sensor controls what?

There's the round one in the middle (slightly difficult to see). And the larger pyramid shaped one to the right.

I had my windshield replaced recently and now my headlights come on too soon (not dark enough).

I asked the SafeLite guy what was the hardest part about changing the windshield. His reply: "putting the rear view mirror electronics back in place".

I brought the car to the dealership for its 10,000 mile service, asking them to check this. Their report: "works properly, no problem found". This is after I told them that the headlights were on for the 25 mile drive to the dealership, from my house at 8:30 - 9:00am under blue skies. Not one cloud in the sky.

I've searched here and Google for help on this assembly. Before I take things apart, I'm hoping someone might be able to provide some insight beforehand.

Thanks - Jim

The Fat Kid

Did you have an OEM windshield installed? Installers will often use less expensive brands unless you specifically request OEM.

StormRune

The brightness sensor for detecting sky brightness is actually the roughly 1" blackish-red rounded rectangle on the dash just inside the windshield (below your photo, on the actual dashboard).

The inverted flattened V you see at the right of your photo is the camera used for automatic high-beams. It looks for the headlight and taillight pattern of other cars.

The sensor in the center of your photo is an IR diffraction sensor with an infrared LED emitter (top clear part) and sensor (bottom darker part) that controls the automatic rain-sensitive wipers.

StormRune

Do you by any chance have something sitting on your dashboard covering the rectangular sky sensor? If you didn't realize that is where it was, then anything in the bottom center windshield area, like a radar detector or dash cam mounted low on the windshield would occlude it and would trigger the headlights turning on.

Looking at the photo more closely it looks like I see something below the mirror. What is that? A mirror-mounted detector shouldn't cause a problem I'd think unless it sits above the sensor.

vwduud

Yes. The only option for this car (at the time, about a month ago) was an OEM replacement.

The Fat Kid

Audis can have issues with replacement glass, so figured I would ask

vwduud

It did cross my mind that the sensor on the dash may be the one controlling the headlights (auto ON/OFF). Is this what you are referring to as the sensor that does control the headlights (auto ON/OFF)?

My automatic high-beams and rain-sensitive wipers still perform as expected (properly).

StormRune

Yes, that is the one that controls headlights on/off.

vwduud

Correct. I have a BlendMount radar detector mount, mounted on the rearview mirror stem. As you pointed out, it is far away from the sensor on the dash. This mount and radar were present before the windshield was replaced, when the auto headlight ON/OFF worked properly. There are no other objects on the dash, near the sensor. I do not have a dash cam.

Porsche_nuts

give the windshield a real good cleaning inside and out?

StormRune

Yeah, this is curious. Do the headlights ever turn off? It's not 100% clear from your post so I just want to make sure. In cases where they are turned on when they shouldn't, I'd be curious to see how it would respond to shining a bright light directly on the sensor.

I'm far from saying this happened in your case, but on a Toyota of mine a decade ago a Safelight guy sliced the front edge of the dash with the trimming knife they use to trim away the old sealant. They didn't say anything about it but I luckily spotted the 3 inch slit when I was picking up the car and was checking their work! They said "oops, we didn't notice we did that!". Right. I would very much doubt this the windshield guy had a errant knife that slipped in under the edge of the dash and cut the sensor wire... but so far that is the only remaining thing I'm coming up with (other than making sure you checked the obvious "duh" things like having the headlight switch turned to "on" instead of "auto").

vwduud

While I have cleaned the outside since having the windshield replaced, I can't say for sure that I have cleaned the inside. Although it doesn't look dirty, that is certainly easy enough to do. I'll give that a try.

Thanks - Jim

vwduud

Yes, they do still turn off. On days where they don't turn off, if I turn the vehicle, facing back into the sun (as opposed to the sun coming from rear), they will turn off. If driving mid-day, on a sunny day, the headlights stay off. It's as though the sensor is just slightly more sensitive, coming on "earlier" and staying on "longer".

In searching for solutions (Google), I did see where other manufacturer's offer and adjustment for this feature (similar to our adjustment for the auto-rain sensing wipers, but was a user selectable setting). I failed to find that Porsche offers such an adjustment or setting. Is this correct? No setting to adjust headlight ON/OFF sensitivity?

Archimedes

Turn lights off?

vwduud

What are you asking specifically?