Twilight sentinel
 

Has anyone else had an issue with this sensor? My headlights are always on. If I shine a flashlight on the sensor, the headlights turn off. If I remove flashlight they turn back on. I’ve never had an issue with one of these sensors in any gm vehicle I’ve ever owned. Thanks

Sounds like the automatic headlamp sensor (or ambient light sensor) is failing.

The plastic "dome" fell off mine, so I replaced it.

FYI it can be changed without removing the dash, but only" just" in reach (long thin arms required) just lower the compartment door, the sensor is "twsit-n-lock"

I have a Blazer that is having the same problem. Unless the full sun is literally directly overhead and shining directly on the sensor they stay on all the time. Pretty much they might cut off 10% of the time during the day. Been meaning to order a new sensor for it, just have not gotten around to it yet and its been like that for a year.

That's good to know, I don't want to pull dash trim again if I don't have to.

Finally got this fixed. I tried a used junkyard sensor and it had the same symptoms. I had to buy a new one. The new one is slightly different in appearance but functions correctly. Ours is a 4 wire sensor by the way.

How easy was it to access and replace?

Easy, just reach through glove box like you said.