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I recently acquired a '98 STS, and live in Phoenix, AZ. I like the auto-on feature of the Twilight Sentinel, however, it comes on too early in the evening IMHO.

The lights turn themselves on about 2 hours before sunset, and remain on up to 2 hours after sunrise, seeming like anything less than direct overhead sunlight does not affect the sensor in the dash. This is bothersome as the dash lights dim when the exterior lights come on, and the dash becomes difficult to read when its dim and there is still bright sunlight outside.:annoyed:

I have kept the area around the sensor clear, and I have cleaned the sensor itself. I am wondering if anyone knows of a way to adjust its sensitivity. Is there a way to affect what it considers to be "dusk/twilight"?

This is NOT a question about adjusting the auto-off timer, that is easy and I've got it figured out....:cool:

Thanks!
 

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'05 XLR
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Hmmm - interesting question. I've never heard of the sensitivity being adjustable. However, have you tried comparing your car with another car equipped with the Twilight Sentinel in terms of when it comes on and off - perhaps the sensor is faulty and could be replaced? On my car is seems the sensitivity is better suited to triggering the lights when I would expect it to.
 

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1992 STS / 2005 MB G500 / 2003 STS / 2006 XLR-V
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No.

I also thought mine was bad, but my lights were ALWAYS on, in my case it ended up being that the wiper stalk was left in INT, which any ON wiper position will cause the lights to remain on. I suspect your sensor is bad.
 

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Is there any way that I can turn this feature off at all??
I just got HIDs installed on my 97 Seville and don't want them to react everytime I drive into tunnels or underground parkade and ETC.
Thanks guys in advance!!
 

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I have the opposite problem. My lights don't come on untill it is almost completely dark. Now that it is starting to get light in the morning, I have to maunally turn on my headlights on the way to work because the twilight dosn't kick in. Also It is hard to see the dash as the dash light's only come on with the light sensor and not the light switch.
I was wondering about a sensitivity setting also. This would be the best way to fix my problem.
I guess I could try putting some window tint plastic over the sensor and see if that helps.

Any Thoughts ??????


Jim
 

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85 Eldo Biarritz
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My opinions are based on my ownership (85 and 93 Eldo), so yours might be slightly different.
Twilight Sentinel is not user adjustable and it is a mixed blessing.

When I got my 1st caddy (the 85) I thought it was a cool feature. But it does have its problems. It used to turn on and off right before sunset when I was driving through a wooded areas (where light level would constantly change). It turns on if you stop under a dark overpass during the day. It would turn off if I was stopped under a really bright street light!. I learned how to either turn it off or turn the headlight switch on so that my headlights don't do the "funky flash". :bonkers:

When I got my 93 Eldo, I figured that Caddy has improved this circuit, so it would work more realistically. Guess what - it works the same as my 85! It does all those funky bad things too.

This is a pretty simple circuit. A photo-resistor (changes resistance depending on light) is mounted in the dash facing up into the sky. It is hooked up to a circuit which filters the input (provides a delay so that the lights don't flash as you going under streetlights). That filter just slows down the response of the circuit which actually turns on headlights if the filtered circuit signals that the outside world is dark, and turns them off it the outside world is lit.

I would have hoped that the newer twilight sentinels would have several sensors (one pointing up, one pointing diagonally to the rear and maybe another to the front or side), so that its decision would be based on several light directions, not just on the "sky". No such luck in my 93 Eldo.

On both of my Caddies Twilight Sentinelt can be turned off (there is an OFF legend on the knob or slider).

If you want, you could fool around with it to get it to come on at different light levels.
Optically, you could reduce or enlarge the opening wich allows the light to enter that photoresistor. That photoresistor is mounted in a transparent blue housing with a black painted face. There is a small openning in that painted area which lets the light in.

Electrically, you could place a certain value resistor in series or in parallel with the photoresistor. That would shift its trigger point.

Way too much work to bother with it...

Peteski
 

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peteski said:
Electrically, you could place a certain value resistor in series or in parallel with the photoresistor. That would shift its trigger point.

Peteski
I might actually do this. At work I have access to 100's of resistor values so maybe I will look into doing this.

Jim
 

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2010 DTS
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Back in the '70's there was an adjustment for sensitivity. I used to adjust every one I had to my liking. You had to get under the dash and do it on the twighlight sentinal unit. I'll never understand why they did away with that feature. I sure miss that feature.
 

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99 STS
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Yes you can adjust it or turn it off ...I turned mine off by sliding the lever under the light switch all the way to the left. No more early lights, but the dash shows "Headlights Suggested" when its getting dark, again when its really not that dark yet.
That same lever I believe adjusts the sensitivity as well, not sure on that though.
 

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The Delay Slide switch (pot) only affects the delay before the lights turn off.

I think I have fixed my problem by using a paint marker pen and just writing over the little window(hole) in the sensor. This blocks some of the light from entering the photo cell. I still need to test it, Daylight savings has messed up my testing.

Jim
 

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99 STS
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Hmm, well I thought my info was correct. BUT I know the lights don't go on themselves because it will show "Headlights Suggested" on the display until I actually turn them on.
I'll check into this...
 

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1991 Cadillac Brougham D'Elegance 5.7 Litre, 1994 DeVille
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jkindley is right. All that does is set the amount of time the headlights will stay on after you turn off the car. But If you go all the way to one side you can turn it off so that the headlights won't work automatically at all. That's probably how you set yours.
 

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1996 STS
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All the way left to the "click" will disable sentinel leaving you with the "pull" method on the knob.

I love not having to mess with the lights, however, sentinel is acting funny sometimes activating lights when plenty of sunlight is hitting the photo sensor. Turn off and restart and DRL's come on as supposed to. Go figure. Not a big deal. But it does irk me knowing theres something wrong somewhere.
 

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brougham said:
jkindley is right. All that does is set the amount of time the headlights will stay on after you turn off the car. But If you go all the way to one side you can turn it off so that the headlights won't work automatically at all. That's probably how you set yours.

I checked and my original statement was accurate...slide it all the way to the left and lights will not go on or off automatically.
 
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