On the rearview mirror

[Harry Ford]

On the front of the interior rearview mirror housing there's what looks like a small square sensor. What's it for? A friend suggested recently that it might be part of an optional auto-dim feature for the Fiesta's hi-beams, but I've never heard of that being offered.

Harry

[wuzzzer]

The rear view mirror has an auto-dimming feature, it is probably a sensor for it.

[Harry Ford]

Originally Posted by wuzzzer

The rear view mirror has an auto-dimming feature, it is probably a sensor for it.

That was what I thought too, except the mirror has a tiny "spot" in the upper/center of the glass that I think takes care of that. Maybe putting an auto-dimming sensor on the front of the mirror "reads" the light being reflected off the inside of the windshield and adjusts the mirror that way?

Harry

[Squirrel]

I had never noticed that until last weekend when I had a friend riding in the car with me and she asked what it was.
I still don't know.

Is the auto-dimmer standard on all of the Fiestas?

[Paradocks]

Originally Posted by Squirrel

I had never noticed that until last weekend when I had a friend riding in the car with me and she asked what it was.
I still don't know.

Is the auto-dimmer standard on all of the Fiestas?

I know it's standard on the SEL/SES. According to the Ford website it is not available on the other Fiesta models.

[CertifiedEvil]

It is indeed an auto dimmer

[Audrey]

Originally Posted by Paradocks

I know it's standard on the SEL/SES. According to the Ford website it is not available on the other Fiesta models.

Correct. It was a surprise feature I learned about on my drive home with my Fiesta. (: Similar to the side mirror blinkers it's only in SES/SEL. The little square is the sensor.

[Squirrel]

My car is an SE and it has the little sensor, but the mirror has the flipper to change it in day/night.
So ... hmmm.

[Mustang Man]

The sensor on the front reads whether it is day or night outside, if it senses it is night out and headlights come up from behind you there is a sensor on the backside(side with the mirror) that picks up that light and dims the mirror.

I have not sat in a Fiesta since I did maintenance on one of the Fiesta Movement cars awhile back so if anyone has a picture of their rear view mirror I can confirm what I said above. What I said above is how every other auto-dimming rear view mirror I have seen works.

[Paradocks]

Originally Posted by Mustang Man

The sensor on the front reads whether it is day or night outside, if it senses it is night out and headlights come up from behind you there is a sensor on the backside(side with the mirror) that picks up that light and dims the mirror.

I have not sat in a Fiesta since I did maintenance on one of the Fiesta Movement cars awhile back so if anyone has a picture of their rear view mirror I can confirm what I said above. What I said above is how every other auto-dimming rear view mirror I have seen works.

Makes sense, since the mirror will not dim when it is light outside, even if someone comes up behind you with their headlights on in broad daylight.