I can turn mine on (and off) and the LED on the mirror bottom responds, but I'm not sure if the mirror is defective or not since I NEVER experience any dimming effect, be it the interior mirror, nor the exterior mirrors which I'm not sure have the electrochromic option fitted.

Where exactly is the light sensor for the electrochromic mirror located? I want to shine a light on the sensor to force a dimming situtation to test the mirror. Are there any other more effective testing procedures to test the electrochromic rearview mirror(s), not that I would consider replacing them?

 

I believe the light sensor is on the left side of the mirror facing the window, the LED light on the right - per the picture I borrowed. I don't know if all mirrors' light sensors are in the same place, since there are different mirrors.

However, I have used Radar-Mirror to fix mine, and it was $99 without shipping and he replaces the light sensor and all in 1 day. I am very happy with the work, and it works perfect now.

If it was working, you would have noticed the effect.

 

After all these years I thought that the sensor on the back of my mirror was for the auto day/night headlights. My mirror dims when I push the switch on the bottom of the mirror -- day or night -- and doesn't seem to be sensitive to daylight or following headlights. Can someone clear my addled brain?

98 XK8 Convertible

 

Sambo21 - Mine has two sensors. One on the windshield side, which is the auto day/night headlights, and the other is on the side facing the driver at the bottom that does the auto-dimming.

I had to do something about my rear view mirror, since it did not work, and the fluid stained the mirror, so I had a piece about 1 inch x 0.5 inch to use as a mirror. I got it fixed, and now it works perfectly. The auto-dimming can be switched on and off by the button on the bottom of the mirror. If on, there is a LED light on the right side facing the driver)

At night, when I get cars behind me, you can see it dimming, and go back to normal once the car or the lights are gone. It is really like magic! Sorry, sometimes small things can bring some amusement to my life, and this is one of them.

 

JSC> Thanks for clearing this up. After 15 years of ownership I finally understand, as the O/M does not have a clearly-written explanation. BTW - I replaced my original "melted" mirror many years ago with the rebuilt one as discussed in another post.

Sam

 

Thanks JSC, you are absolutely correct. I had another look today in broad daylight and indeed the dim sensor is buried in the left-side hole on the lower edge of the mirror frame. Now I'd like to know how to dismantle and remove the mirror to send it to Radar-Mirror for the repair. Your help is very much appreciated.

BTW, I'll have to double check whether there is an auto day/night headlight sensor option installed in my XK8. As my Jag is a native Hong Kong car which did not even have the cruise control option, it may very well not have the auto day/night headlight option.