# Automatic lights

**URL:** <https://community.cartalk.com/t/automatic-lights/89646>\
**Category:** General Discussion\
**Tags:** fleetwood, cadillac\
**Created:** [April 13, 2015, 7:02am UTC](https://community.cartalk.com/t/automatic-lights/89646 "2015-04-13T07:02:58Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![moecrulylarry](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@moecrulylarry](https://community.cartalk.com/u/moecrulylarry)\
**Post date:** [April 13, 2015, 7:02am UTC](https://community.cartalk.com/t/automatic-lights/89646/1 "2015-04-13T07:02:58Z")

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93 fleetwood - bought new - automated headlights, they worked fine for 20 years, now they are delayed from 30 seconds to 1/2 mile down the road. i can physically turn them on, it’s just now automatic / instant as it use to be. any ideas

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**Author:** ![oblivion](https://avatars.discourse-cdn.com/v4/letter/o/3ab097/32.png) [@oblivion](https://community.cartalk.com/u/oblivion)\
**Post date:** [April 13, 2015, 2:37pm UTC](https://community.cartalk.com/t/automatic-lights/89646/2 "2015-04-13T14:37:21Z")

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I’m not familiar with the system on your car and its features. Are they not coming on as fast when it gets darker, or not dimming for oncoming traffic? If not coming on that fast, some of these have a manual adjustment somewhere for the sensitivity. If not dimming for oncoming traffic, find the light sensor and try cleaning it.

If all else fails, 20 years use is not an unreasonable amount of time to expect any system to degrade somewhat.

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**Author:** ![missileman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/missileman/32/1366_2.png) [@missileman](https://community.cartalk.com/u/missileman)\
**Post date:** [April 13, 2015, 5:18pm UTC](https://community.cartalk.com/t/automatic-lights/89646/3 "2015-04-13T17:18:53Z")

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+1 for **oblivion.**

This is probably a good time to bring up a gripe of mine about automatic lights. All vehicles with DRL do not have automatic lights. I see a lot of new vehicles running after dark with no tail lights. The most recent example was an uncle of mine who owns a 2015 Ford. He passed me on the interstate on a multi-family trip and I had to call him to tell him to turn on his headlights. When we stopped at the next rest area he was upset that his lights did not turn on automatically like his last car did. I told him the same thing that I’ve already stated here…not all new vehicles have automatic lights even if they have DLR. They should…in my opinion…but they don’t.

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**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\
**Post date:** [April 13, 2015, 7:27pm UTC](https://community.cartalk.com/t/automatic-lights/89646/4 "2015-04-13T19:27:10Z")

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If they are automatic headlights, the photocell that senses the light may have degraded. The sensor is usually located at the base of the windshield under the defogger grill. If you decide to pursue this, what you might want to do is request of the dealer parts window guy an “exploded view” drawing of the dashboard area that includes the sensor.

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**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [April 13, 2015, 8:51pm UTC](https://community.cartalk.com/t/automatic-lights/89646/5 "2015-04-13T20:51:31Z")

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Hmmm…The OP previously told us about problems with this car’s radio, cruise control, and A/C. Now there is a problem with the automatic lights.

Is it possible that he needs to replace the BCM?

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**Author:** ![sgtrock21](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/sgtrock21/32/246_2.png) [@sgtrock21](https://community.cartalk.com/u/sgtrock21)\
**Post date:** [April 13, 2015, 9:58pm UTC](https://community.cartalk.com/t/automatic-lights/89646/6 "2015-04-13T21:58:17Z")

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VDCdriver: Does BCM stand for Basic Car Module? lol

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**Author:** ![Docnick](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@Docnick](https://community.cartalk.com/u/Docnick)\
**Post date:** [April 14, 2015, 12:03am UTC](https://community.cartalk.com/t/automatic-lights/89646/7 "2015-04-14T00:03:11Z")

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BCM is Body Control Module, as opposed to the Engine Control Module (ECM). It controls all the non-engine functions in the car.

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**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\
**Post date:** [April 14, 2015, 1:07am UTC](https://community.cartalk.com/t/automatic-lights/89646/8 "2015-04-14T01:07:01Z")

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Nice catch VDC. You might be right. Unfortunately, I know of no way to test the BCM on a '93. Does it even have one??

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**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [April 14, 2015, 1:25am UTC](https://community.cartalk.com/t/automatic-lights/89646/9 "2015-04-14T01:25:20Z")

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**"Does it even have one??"**  
I don’t actually know the answer to that question, and my suggestion was sort of a WAG.

My reasoning is…even if some cheaper models didn’t yet have a BCM in 1993, I think it is very possible that a '93 Cadillac would have one, in light of having more accessories/more bells and whistles than cheaper models at the time.

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [April 14, 2015, 7:56am UTC](https://community.cartalk.com/t/automatic-lights/89646/10 "2015-04-14T07:56:41Z")

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I’m not familiar with the Cadillac setup but it could be that the headlight switch is failing and my vague memory seems to recall that the twilight sentinel is part of the expensive switch.

My vague memory also seems to recall a dealer I worked for cursing the price of a few auto headlight switches that he had to buy as a repair on some used cars before placing them for sale.  
He was really riled up over the near 900 dollars after discount Lincoln switch… ☹

Before wading into big bucks on a wild guess switch replacement I would suggest some digging for a diagnostic chart and making sure that switch is faulty before pulling the trigger on a purchase.  
Depending upon the tolerance for financial pain, leaving it as is could be an option.

The car is going on 25 years old so a few hiccups at this point are to be expected.

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**Author:** ![bing](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bing/32/4619_2.png) [@bing](https://community.cartalk.com/u/bing)\
**Post date:** [April 14, 2015, 9:09pm UTC](https://community.cartalk.com/t/automatic-lights/89646/11 "2015-04-14T21:09:04Z")

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I’d suspect you have a problem with the photo cell itself that flips the switch to turn the lights on. You do realize the lights don’t go on though unless it’s dark. You could try cleaning the sensor and trying a new fuse or circuit breaker just to rule that out.
