Photochromic mirror
 

Okay, this might be a dumb question, but I don't see it referred to at all in the owner's manual. I have an '02 Lariat, and my question concerns the electric photochromic rearview mirror. This is the windshield mounted inside mirror with the "off" and "auto" buttons on the bottom front of the mirror. Now, on the opposite side of the mirror, the side that faces the front of the truck, there appears to be a small square window in the housing which looks like a small sensor eye. Does anyone know what this is, and what function it is supposed to perform?
Thanks.

I have a similar one on my 01 Expy. It serves the same function as the old mirrors with the flip lever on them, but does it electronically. Helps reduce glare frome headlights on the cars behind you. With the switch turned on, the mirror will change to a greenish shade and glare will be reduced. With the switch off, nothing happens.

Yes, I know all that. I love the feature. What I wanted to know is what is the function of the square opening on the front side (the side that faces the front of the truck, not the mirror side). If you take a look at your mirror from outside your truck while standing in front of the grille, you will see a square opening that could be a light sensing cell. I wanted to find out what that is and what is it's function. I have no clue since it isn't covered in the owner's manual. A hidden Ford feature? I'm stumped.

Its a light sensor so the Mirror doesn't shift during the day. Its got a higher resistance (time delay) than the one that shifts the mirror. The tunnels in Baltimore screw the mirrors up, because they are so bright at night. Takes awhile when you come out of the tunnel for the mirror to start working correctly.

Damn, I thought it might have been a sensor eye for automatically dimming the high beams when it senses oncoming traffic.........
Thanks for the help.:beers: