Interior Rear View Mirror Sensor

[Lowufo]

Does anyone know what the sensor is on the back of the rear view mirror in my 2005 Yukon? The automatic headlight sensor is on the dash right? So curious what this would be for. Truck does have Onstar but no auto wipers

 

[S33k3r]

I suggest getting a picture of it. It is always possible you have an aftermarket mirror with a forward facing camera.

 

[Lowufo]

Definitely not an aftermarket mirror. Upon further inspection I would have to say it is a sensor for dimming mirror.

 

[adventurenali92]

Definitely not an aftermarket mirror. Upon further inspection I would have to say it is a sensor for dimming mirror.

View attachment 267211

Yes that’s the sensor that picks up ambient light, and will cause the backlighting on the mirror itself to go on and off.