# Blue blinking light on people's dashboards/sun visors? **URL:** \ **Category:** Factual Questions\ **Created:** [December 5, 2018, 12:52am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576 "2018-12-05T00:52:48Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Asuka](https://avatars.discourse-cdn.com/v4/letter/a/dec6dc/32.png) [@Asuka](https://boards.straightdope.com/u/Asuka)\ **Post date:** [December 5, 2018, 12:52am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/1 "2018-12-05T00:52:48Z")
Driving home from work every night when I hit residential neighborhoods I’m noticing more and more cars have a blue light that slowly blinks on either their dashboard or sun visor. The fact I’m seeing it means it’s pointing outside the car so I have no idea of its purpose. The light is bright blue and seems to blink every 5 seconds or so after staying steady. ---
**Author:** ![pool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pool/32/4152_2.png) [@pool](https://boards.straightdope.com/u/pool)\ **Post date:** [December 5, 2018, 1:14am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/2 "2018-12-05T01:14:51Z")
My guess is that the light you are seeing means the car is locked and the alarm is armed. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [December 5, 2018, 1:20am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/3 "2018-12-05T01:20:43Z")
> [@pool](#): > > My guess is that the light you are seeing means the car is locked and the alarm is armed. Correct, although in some cases it’s a fake light so would-be thieves assume the car is alarmed. ---
**Author:** ![excavating\_for\_a\_mind](https://avatars.discourse-cdn.com/v4/letter/e/e8c25b/32.png) [@excavating\_for\_a\_mind](https://boards.straightdope.com/u/excavating_for_a_mind)\ **Post date:** [December 5, 2018, 1:43am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/4 "2018-12-05T01:43:33Z")
> [@pool](#): > > My guess is that the light you are seeing means the car is locked and the alarm is armed. I thought these were red. I guess they have to switch things up to stay with the times. ---
**Author:** ![zombywoof](https://avatars.discourse-cdn.com/v4/letter/z/9e8a1a/32.png) [@zombywoof](https://boards.straightdope.com/u/zombywoof)\ **Post date:** [December 5, 2018, 1:44am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/5 "2018-12-05T01:44:58Z")
Dashcam. ---
**Author:** ![pool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pool/32/4152_2.png) [@pool](https://boards.straightdope.com/u/pool)\ **Post date:** [December 5, 2018, 1:56am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/6 "2018-12-05T01:56:44Z")
Fleshlight is charging… ---
**Author:** ![ThelmaLou](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thelmalou/32/390_2.png) [@ThelmaLou](https://boards.straightdope.com/u/ThelmaLou)\ **Post date:** [December 5, 2018, 2:09am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/7 "2018-12-05T02:09:34Z")
To me a blinking blue light means a Bluetooth device is paired. That’s all I got. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [December 5, 2018, 5:45am UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/8 "2018-12-05T05:45:12Z")
> [@zombywoof](#): > > Dashcam. Yes. My dashcam, mounted in front of the rear view mirror, has a blue LED light. It blinks when recording an incident and is otherwise solid blue. There is a red light on top of the defrost vents that blinks when the car is locked and the security system is automatically armed. ---
**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\ **Post date:** [December 9, 2018, 9:00pm UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/9 "2018-12-09T21:00:03Z")
They are against the law in North Carolina as they could misrepresent the car as being a police vehicle. Also red lights that are not originally on the car. > **[GS\_20-130.1.pdf](https://www.ncleg.net/EnactedLegislation/Statutes/PDF/BySection/Chapter_20/GS_20-130.1.pdf)** > > 13.22 KB ---
**Author:** ![zombywoof](https://avatars.discourse-cdn.com/v4/letter/z/9e8a1a/32.png) [@zombywoof](https://boards.straightdope.com/u/zombywoof)\ **Post date:** [December 9, 2018, 10:46pm UTC](https://boards.straightdope.com/t/blue-blinking-light-on-peoples-dashboards-sun-visors/825576/10 "2018-12-09T22:46:42Z")
> [@Ignatz](#): > > They are against the law in North Carolina as they could misrepresent the car as being a police vehicle. Also red lights that are not originally on the car. > > [https://www.ncleg.net/EnactedLegislation/Statutes/PDF/BySection/Chapter\_20/GS\_20-130.1.pdf](https://www.ncleg.net/EnactedLegislation/Statutes/PDF/BySection/Chapter_20/GS_20-130.1.pdf) Not according to the law you posted - these blue lights are not of the sort “designed for use by an emergency vehicle, or (is) similar in appearance to a blue light designed for use by an emergency vehicle”