LED DRL and turn signals
 

Just merely wanting to understand the behaviour here.

So most if not all cars nowadays have a DRL strip/lighting. On some cars the DRL temporarily turns off one one side when the turn signals are activated and then re-enables again when the turn signals end. I always assumed this is so that the DRL and the turn signals don't compete against each other for visibility.

Others have the DRL strip/lighting stay on full time even while the turn signals are activated.


I noticed on my 86 that the first condition happens in the daytime when its just the DRLs and no headlights. (One side DRL turns off when the turn signals are activated)

But at night when the headlights are also on, the second condition happens (all lights stay on)


Anyone know why this is? Is it just at night its easier to see all the different lights so that the DRL's dont need to be turned off?

That's probably the reasoning there. Your DRL also dims when the mains are on, yes? This would also help the lights to not compete.

It has to do with the law. If the turn signal is in the headlight along with the DRL then the DRL needs to turn off. This is how my wife’s Q5 is set up to do. At night, the DRL dims and the headlight needs to stay on, so those are still illuminated when the turn signal is on.

https://jalopnik.com/heres-why-moder...hen-1792394567

I only really ever pay much attention to this when im behind another vehicle at a light and i can see the distorted reflection of the front fascia in their bumper or tailgate.

I never actually noticed the lights dimming at night though....maybe next time if i pay attention to it i'll see.
but daytime its obvious that the DRL turns off when the signals turn on.

I just thought the car would be using one of the two behaviours instead of using both.

Some DRLs turn off. Some dim. My wife’s Q5 dims. It is hard to tell because at night the DRLs look just as bright as they do in the day based on the contrast.