Automatic headlights are a HUGE safety concern!

Several years ago, I rented a Mustang convertible. It was my first experience with automatic headlights. It was starting the get dark and the headlights and dash lights came on. I assumed (I know…bad word) that the taillights were also on. But while stopped at a stoplight, someone told me that my taillights were not on. REALLY? Recently, I encountered a brand new car (had paper plates) where the headlights were on, but there were no taillights. I felt this was a VERY dangerous situation! The driver pulled in behind me in a turn lane. I got out to warn him. He had NO idea!

I truly believe this is a very good idea with very POOR execution! New car buyers (and renters) are given a false sense of security with these automatic headlights. They have no idea that they won’t have taillights until they actually turn the lights on with the switch.

I believe that if car manufacturers are going to provide this “safety” feature, that they should be turning on ALL lights, not just the headlights and dash lights.

Fremont, CA

Swil, I’m Not Sure What You’re Describing And Warning About, But None Of It Pertains To The Many GM Cars In Our Driveway !

We have and love DRLs. We have had them for many, many years and hundreds of thousands of miles. We never have to touch the light switch.

When it’s fairly light out then only the DRLs light. When it’s dark overcast or dusk, dawn, or nighttime then all lights, headlights, taillights, dash lights, etcetera, are ON - Every Time ! No Fail ! No Fooling !

I’m not sure what you’ve experienced.


Sounds like GM got it right, then! :slight_smile: “I’m not sure what you’ve experienced?” I thought I was quite clear in describing what I’ve experienced. I think the guy, the other day, was in a Toyota and I had direct experience with a Ford. Would be interested to hear from drivers that HAVE experienced this phenomenon, as it seems that some car manufacturers are turning on all lights and some are only turning on the headlights.

When the auto headlights come on in my 2006 Toyota the tail lights come on too.
My only beef is that in the twilight hours they will go on and off in the shadows of trees, buildings, underpasses etc.
Then I just turn them on manually.

“My only beef is that in the twilight hours they will go on and off in the shadows of trees, buildings, underpasses etc.”

CS, the automatic lights on our GM vehicles have built in quite a delay (several seconds) before kicking in or out so that they don’t go on and off in shadows and such as you describe. It’s engineered that way for just that reason.


Our two Ford products have all lights come on automatically. There must have been something wrong with the Mustang.

Ditto to those who stated that there must have been something wrong with the Mustang in question. While DRLs don’t cause tail lights to go on, the automatically-activated headlights on every car with which I have come into contact cause the tail lights to be activated as well.

Perhaps the OP is confusing DRLs with automatic headlights.

CSA, I didn’t describe that very well.
There is a “low pass filter” delay of 15 seconds or so, so individual shadows don’t trip it.
But going from a street with trees or tall buildings to one without, or clouds rolling by etc. can cause cycling up to once or twice a minute.

MY '05 Camry works just fine, the delay prevents repeat on & offs.

I have seen a few cars drive around at night with the headlights on and tail lights off and I know what the OP is referring to. It is dangerous. Now I have to make note of the make & model of these cars.

FWIW, my '09 Mazda CX-9 does NOT have DRL’s which I find interesting (car has blue tooth and bunch of other gadgets).

Me thinks the OP may have had the DRL’s activated. In which case the tail lights would not come on.

Wouldn’t it be a goid idea to wire the instrument panel lights to the same power source as the taillights, then?

I’ve driven old-fashioned cars in urban environs where you didn’t miss not having headlights, but the black instruments clued me in right quick. Given that DRLs are for “ample-light” use, why would you even want instrment lights?

SWIL. What you have described are the Daytime Running Lamps, not automatic headlamps. Automatic headlamps illuminate all required lamps.
DRL operate the headlamps only. In some vehicles the DRL operate the lamps at less than full power.

The tailights go on on my Acura, Olds, and Pontiac just like they’re supposed to. Maybe you are talking about the DRLs or daytime running lights. Those only turn the headlights on all the time and not the tails. There might be a separate circuit breaker for the tails though that should be checked. When I was having problems years ago with my Riviera twilight sentinal, there was a separate breaker for the headlights and the rest of the lights. Personally, I think the DRLs should also illuminate the tails. People in snow and fog during the day drive around with with DRLs but you can’t see the rear of the car. I usually just cover the sensor in low light daytime to turn the lights on instead of using the switch. Then I don’t worry about turning them off again.

OK…it looks like I used the wrong term. Being a 2002 Miata driver, without any automatic lights of any type, I wasn’t familiar with DRL vs. automatic lights. So it seems that what I am referring to is DRL’s. That said…let me ask this…if DRL’s are on and it gets dark, the end result is what I’m describing, correct? The headlights and dash lights are on, but no taillights. So what would be the best way to avoid this scenario? It just seems like the technology should be there to somehow warn the driver that they are driving without taillights or something?

Thanks all for the response!

DRLs are there so other drivers see you. They’re not there to help you see anything. The instrument cluster on some cars is set deep in the dash or illuminated at all times to allow you to see the gauges. You’ll notice that most likely the heater/ac controls or radio aren’t illuminated any differently until you turn the headlamps on. There’s your first indication. The second (I believe) is the warning light in the instrument cluster (usually a green bulb symbol) telling you the DRLs are on and the regular exterior lights aren’t.

I’m generally opposed to safety devices in general, so my opinion doesn’t weigh heavily, but I wonder what the exact benefit of DRLs are.

All of my cars that have had automatic lights have to be selected into that mode with a switch.
If you put it into that mode but someone else de-selected it (like your toddler) then you may believe they are enabled but not know they aren’t. This isn’t exclusive to automatic headlamps. I have seen many people over the years going down the road with just their DRLs on thinking their headlamps/tail lamps were on. If you want to rail against something, rail against DRLs. They precipitate the problem because some people can’t tell the difference in intensity until it gets much darker out. Prior to DRLs, the incidence of this kind of problem was a much more rare event.

There are DRL’s - Daytime Running Lights and there is Automatic Lights (GM’s Twilight Sentinel). They are different!

DRL’s are low power headlights (wired in series) turned on whenever the car is running and the lights are OFF. Turning the running lights ON, lights the tail lights as well as full power (now connected in parallel) headlights. GM realized early on that people were running around at night with just the DRLs on thinking that ALL lights were on. They made Automatic Headlights standard. Ford didn’t. Many other car makers didn’t. So now we have tail light-less people roaming around after dark.

FWIW, I HATE DRLs and disable them on all my cars that have them. They take away the safety of motorcyclists running with their headlights on by confusing motorists. My bike gets lost in the light pollution of these things. It is a BAD idea that should be stopped.

FWIW, I HATE DRLs and disable them on all my cars that have them.

I guess you live in a state the doesn’t have laws on this. In many states you it’s against the law to disable them.

@MikeInNH, I do not know if my state has a law against disabling DRL’s and frankly, I don’t care. I’m taking a stand. My Automatic Headlights illuminate the dark, I always turn on my lights in the rain and when wipers are on (an unknown, unenforced law in my state) but I will not add to the light pollution and confusion caused by DRL’s. It is illegal to run with high beams on (or pulsing) in traffic but many motorcyclists do this in my state because of DRL’s.

I agree with you about DRL. Wife has them on her Lexus. I see no need for them.