When the rear view mirror senses headlights does it angle it self down, or does it tiint the glass(with liquid crystal). Are there any other electronic devices in the mirror?

 

For the interior rear view mirror, if you press the button to turn on the feature, the mirror will auto-dim based on light of day/night.

 

The glass is "photochromic." I don't know if it uses liquid crystal technology to do this, but it definitely dims. It takes a few seconds to do this. If I'm parked in my dark garage with the door open, the bright sunlight from outside dims my mirror. I can turn off the switch on the mirror and watch it brighten. Hit the switch again and the image dims down to a slightly purplish-blue color.

 

that seems cool to have. too bad i have a wide angle view mirror and it totally covers it all up.

anyone know if this feature is "on" if it uses power? im sure it cant be using much if any at all, but might as well have it off if i dont have any use for it right?

 

It probably only draws a couple of milliamps. I doubt one could detect the power usage in the grand scheme things (ie. improved fuel economy, etc.).

 

But letting it sit... So, it dims when in direct light? Or dims at night when everything else is dark?

 

It dims any time light is hitting the sensor, which is visible in the little hole in the bezel under the mirror. It doesn't matter if it's day or night or if the headlights are on. The only thing that affects it is whether or not it is turned on (green LED is lit to show it's on).

 

I'm not sure about that. On a bright sunny day, we do not want ANY dimming. I would expect when the ambient light is low, it dims. Just the opposite of what your pupils do.

When dark, your pupils allow more light and the mirror darkens....

 

Is it tied to the headlights being on in any way? In other words even if the mirror is turned on, will it not dim unless the headlights are on?

 

Not tied to headlights. Mirror works independently and on its own.

 

There are two sensors. One in the back of the mirror (facing the front of the car) which detects ambient light, and the second which is on the front of the mirror (facing the rear of the car) which detects headlights and other bright light sources.

If the ambient sensor detects that it's dark, the light sensor will be "dimmer switch" so to speak. Depending on how bright things are, it will dim the mirror.

To easily test this, cover the ambient sensor with your finger in broad daylight. You will see the mirror dim instantly because now the mirror thinks 1) it's night outside and 2) there is a lot of bright light behind you.

 

MAKES Sense!

 

Would it hurt to leave it "on" all the time? Can it "burn" out if left on for say years?

 

Exactly. This is why it dims when I open my garage door in the morning. The garage is relatively dark but the sunlight from outside pours in and hits the sensor under the glass and dims it.

I don't think it will wear out if used all the time.

 

"Interior"? What other rear view mirror is there?

 

Some refer to the side mirrors as "rear-view," too.

 

That is correct. I have tested it too.

 

Mine still worked after 83,000 miles no problem. But I had it off most of the time. The thing was too sensitive and would dim whenever there was someone behind you. I like to get a better indication of when someone is behind me when I am driving on the highway for passing etc. I felt that it dimming all the time made it more difficult to judge traffic etc. Or tell if it was a state trooper behind you in the dark...

 

My Lexus has the auto-dimming feature on all three mirrors. This makes a big difference and is the kind of stuff Acura has to start doing to compete.