What's the Deal with Headlights on/Taillights off?

What you are seeing is most likely DRL, Driving Running Lights, the headlights are on whenever a person is running no matter if it is raining or not.

The only time I’ve ever had daylight running lamps is when in a rental car.

Since when it gets dark the headlines are still on and plenty bright for driving it has never occured to me that I need to turn the knob on the headlights since that produces no change in the amount of headlight light being produced.

If that is needed for taillights to be on after dark then good to know, but stupid.

My car (in Canada) has 4 light settings - Off, Auto, Park, and On. Off has all the lights off, On has all the lights on, Park has the front and rear marker lights on, but not the headlights. Auto turns all the lights on when it gets dark (including dusk/overcast) or if the wipers are on. For all settings, the Daylight Running Lights come on when the car is in gear. Each light status has a different coloured indicator in the instrument panel - white for DRL only, orange for markers only, and green for full headlights and markers. I leave it on Auto as it turns the headlights on when I would have or even before.

In my previous car it was easy to tell when it was past time to turn on the headlights, as eventually you couldn’t see the instruments, since the instrument panel lights only came on when the headlights were on, (so if you didn’t have your headlights on after dark it meant that you were the kind of driver who never looked at the speedometer or anything else on the panel). In the new one every instrument and control has their own little LED built in, so not the same indication.

I’ve found that since automakers have started illuminating the DASH lights at all times, people are having trouble noticing that they haven’t illuminated their full headlight beam (i.e. not DRL).
I’ve been caught out by this before in rental cars myself. I see the dash all lit up, and I think that my headlights are on. The (meager) light being thrown by the DRLs further confuses the situation.

Every time I pass someone on the highway at night, who doesn’t have their lights on, I notice through their drivers window that almost without fail the car’s dash is illuminated.

Just quoting the above, although my comment applies more generally to other responses in this thread and indeed behavior on the highways.

Do daytime running lights illuminate the dashboard lights? I don’t recall for sure, but I think not. Are all these people driving around without visible instruments? How do they know what speed they’re going?

…Or build a floor strong enough to handle when they stamp their feet…


Also, does this thread handle all those cars who, just this winter, seem to have just one head light burned out?

Or is this a Crips thing?

Fully half the drivers in Florida are already dead and are just faking it, so, yeah.

If I am remembering right, mine do. When I actually turn on my lights, the dash dims since it assumes it is now darker out.

I have had to flash my lights a couple of times at people in dark-colored cars who forgot to turn on their lights, and it was truly dark out. They were creating something of a hazard.

My headlights are always on when I turn my car on , we are suppose to put our lights when we needs to use our wipers but a lot of people don’t do this. I do b/c
I don’t want to get a ticket , you never know when a police will actually do their job stop you for this in my city. I see that too headlights on and taillights off , I put my taillights on in bad weather . I like that my new car is loud enough for me to hear I left my lights on. Someone had the smarts to made the warning sound so hoh people can hear it too.

tl;dr

Traditionally, the taillights were on a different circuit than the headlights.
A blown fuse could take out the taillights and leave the headlights functional.

I always turn on headlights if there is even mottled light, let alone precip or dark - I want to give the other idiots the best possible advantage in seeing me (black truck),

Yes, & most of them were spry young 16 year olds when they got into line at the DMV!

I know this is a zombie but I’ve always thought turning on the headlights during the day is a waste. Sure, it may, in a tiny way, help someone see you better, but its daytime! Its not going to help that much! And there’s a better chance of me forgetting to turn the lights off in the day time or that it will blind someone than avoid an accident. So I don’t do it

This is why I don’t ever turn my lights on even at night. I’m too afraid of blinding all the other drivers and causing them to have accidents and die.

In this country it’s not possible to turn on any lights at the front without having the ones at the rear come on as well.
Even Volvos and Saabs (the only ones built with always-on DRL) are like that too.

Actually it’s more of a matter of how many recent-vintage vehicles have a base illumination/backlight on the main gauge cluster anyway even for daytime mode.

In the case of my car the telltale is that daytime/off mode does not illuminate buttons and panels outside the main cluster but I can read my speed, fuel, temp, tach. When I switch on my lights the instrument cluster actually dims but then I can also see my window switches, AC and radio buttons, etc.

And you would notice something wrong if you tried to drive on my DRL alone in real dark conditions, they light up less than low-beams.

Newer vehicles have “auto” mode that turns on the lights when the outside is dark enough.

Its necessary at night and safer but unnecessary in the day. At night, you live with the consequences because someone’s light is too bright or at your eye level. But in the day, we don’t need them. Turn off your lights in the day

(Zombiehood of thread acknowledged.) Several people have referred to studies showing significant safety enhancement. In my personal experience, on bright days a car can emerge from a shadow, and seem to be appearing out of nowhere. This only happens about once every 8 years, but it’s scary enough that I always try to have headlights or DRLs on whenever I drive.

Isn’t it the law that you have to have you headlights on if it’s raining? Even if it’s daytime. I was always told that anytime my wipers are on, my headlights should be too.

I don’t see any reason for the system not to be entirely automated at this point. No one should have to turn anything on, and the lights should get brighter or dimmer based on ambient conditions. Maybe you might still need a dimmer switch, but ideally the light of the approaching car would be enough to detect that.

And I agree with the OP. The headlights and taillights should be on at the same time. Just less bright during the day.