DRL headlight turning blue

2021 Sierra X31 · August 6, 2021

6 minutes ago, zeon said:

Yep... there’s the post of the guy with both headlights screwed up. I just saw a new AT4 the other day and both lights had turned purple. BTW: I’ve now noticed that Ford has a similar problem on their brand new Expedition LED running light strips.

Misbehaven · September 6, 2021

My two week old Denali has the blue/purple DRL on the driver's side. Going in the shop next week for replacment.

2021 Sierra X31 · September 27, 2021

On 9/5/2021 at 8:52 PM, Misbehaven said:

My two week old Denali has the blue/purple DRL on the driver's side. Going in the shop next week for replacment.

Did you get the light swapped? I’m at GMC waiting on mine right now. Took all day. They had to pull the whole front end off to get the light swapped. If this one goes purple, I’m just throwing the towel in and figure I’ll have to live with it.

sackvilledan · September 30, 2021

I've got the same issue on my 2021 AT4, I've had it for six weeks. Noticed it about three weeks into owning it (brand new). Sales guy says it's under warranty so I'll need to take it in.

Interesting that it's the DRL setting only - when I turn my headlights ON or am driving at night, I don't see the colour difference. It is also not apparent when I autostart the truck and stand outside it with the perimeter lighting is on. I would never have noticed it if not for this forum sparking my mind to check - so thanks!

f8l vnm · September 30, 2021

3 hours ago, sackvilledan said:

I've got the same issue on my 2021 AT4, I've had it for six weeks. Noticed it about three weeks into owning it (brand new). Sales guy says it's under warranty so I'll need to take it in.

Interesting that it's the DRL setting only - when I turn my headlights ON or am driving at night, I don't see the colour difference. It is also not apparent when I autostart the truck and stand outside it with the perimeter lighting is on. I would never have noticed it if not for this forum sparking my mind to check - so thanks!

I believe the C shaped LED DRL become dimmer when the headlights are turned on.

2021 Sierra X31 · September 30, 2021

4 hours ago, sackvilledan said:

I've got the same issue on my 2021 AT4, I've had it for six weeks. Noticed it about three weeks into owning it (brand new). Sales guy says it's under warranty so I'll need to take it in.

Interesting that it's the DRL setting only - when I turn my headlights ON or am driving at night, I don't see the colour difference. It is also not apparent when I autostart the truck and stand outside it with the perimeter lighting is on. I would never have noticed it if not for this forum sparking my mind to check - so thanks!

Exact same here. I Only notice it during daytime with DRLs on. I did get mine swapped 3 days ago. The new one matched the old one in color, so that’s good. I’m kind of just wondering how long before it goes purple again. I do need to adjust the beam on the new light as i can tell it’s projecting lower than my passenger side beam.

dennismc · September 30, 2021

My Sierras DLR lights match when I first start the truck then after a few minutes the driver side top turn a lite blue. I went and checked and mine behaves the same way with headlights on, clears up, off back to blue. Thanks for pointing this out.

OliverDennis52 · September 30, 2021

Same here - going in Monday. Drivers side.

dennismc · September 30, 2021

49 minutes ago, OliverDennis52 said:

Same here - going in Monday. Drivers side.

Seems like the majority, if not all are the drivers side.

2021 Sierra X31 · September 30, 2021

2 hours ago, dennismc said:

Seems like the majority, if not all are the drivers side.

Yes... I agree. I’d say 90% or more are only drivers side... but I did just so happen to see an SLT tonight with passenger side purple also.

And, interesting and quick twist of fate for me. 4 days into having mine replaced, I just noticed today that it’s already turned purple... so... I’m not a happy camper. They had my truck all day, had to pull the whole front end off truck, and 4 days later it’s bad already.

Stand By · October 2, 2021

Wonder if there's a resistor problem for that circuit? Maybe the led itself isn't bad since replacements are so quick to fail?

2021 Sierra X31 · October 2, 2021

1 hour ago, Stand By said:

Wonder if there's a resistor problem for that circuit? Maybe the led itself isn't bad since replacements are so quick to fail?

You might be on to something... it’s really strange that they are failing so quickly. And the fact that it’s only driver’s side on the majority of these trucks points to something also.

Stand By · October 2, 2021

20 hours ago, 2021 Sierra X31 said:

You might be on to something... it’s really strange that they are failing so quickly. And the fact that it’s only driver’s side on the majority of these trucks points to something also.

Yeah, maybe Im wrong, but it just stands to reason. Fine for so long, then when it's bad, the replacement doesn't fix it. Only real test would be to put a "bad" one on a different truck and see if it lights correctly. Maybe the blue is a resistance issue (to much, or to little), causing the light to run in the blue spectrum? I haven't heard of the Silverado sharing this problem. The GMC light seems to be a longer wrap around the headlight bezel and maybe has more LED's to power than the Silverado DRL?

claw2791 · October 3, 2021

On 9/30/2021 at 11:51 AM, 2021 Sierra X31 said:

Exact same here. I Only notice it during daytime with DRLs on. I did get mine swapped 3 days ago. The new one matched the old one in color, so that’s good. I’m kind of just wondering how long before it goes purple again. I do need to adjust the beam on the new light as i can tell it’s projecting lower than my passenger side beam.

Obviously haven't seen yours to say what it does or doesn't need. But usually Driver's side beams are intentionally lower to not blind oncoming Drivers as much. (At least in the US anyway with right lane driving.)

Mine hasn't been replaced and is slightly lower than the Passenger side.

Edited October 3, 2021 by claw2791

2021 Sierra X31 · October 3, 2021

15 hours ago, claw2791 said:

Obviously haven't seen yours to say what it does or doesn't need. But usually Driver's side beams are intentionally lower to not blind oncoming Drivers as much. (At least in the US anyway with right lane driving.)

Mine hasn't been replaced and is slightly lower than the Passenger side.

I’ve heard that also. That probably explains it