Is it turned on? There is a power on switch for the mirror. The left side button below the mirror turns the autodimming off and on as indicated by the green Led.
To test it, while driving, or parked with the key to on, on a sunny or bright day, cover the mirror's front sensor (passenger side toward the windshield). Now it senses it's 'dark' outside AND you have bright lights from behind. It should dim under these conditions. Real Easy way to test it's function.
god questions! Yep, I have power to mirror, and have turned it on. It was working up untill about a month ago. WE're out of warranty now, too.
Second, I did try covering the sensor thing, and nothing happens!
Any other thoughts?
when i bought my 01 the mirror didnt dim and when i brought it back to the dealership i had to fight with them about how it was a safety issue and they finally replaced it. they were gonna have me pay for it saying it was a luxury feature.
Only other thing that comes to mind is a 'dirty' sensor. You can clean the 2 photocell sensors with a q-tip and water, glass cleaner, or I use isopropyl alcohol. I dab the q-tip in the alcohol and clean the front and rear sensor with one end, then dry it with the other.
If it is a dirty sensor, I would suspect the one on the face of the mirror, (facing the rear of the car). That's the one that would sense when there is light from behind and dim the mirror. If it were the front sensor (facing the windshield), the mirror is dim all day, then seems to work properly at night.
Aside from cleaning these, yup, time to replace the mirror. If I had to replace mine right now, I would spring for the extra few dollars for the Homelink Mirror. Same features as the self-dimming compass mirror, but adds the Homelink transmitter. One more thing I don't have to carry in the car, provided your garage door opener receiver supports the homelink type transmitter.
From my experiences, I've changed 2 so far. On other vehicles. Neither was for failure to work properly (to Dim that is). Electronics these days are pretty reliable. Those 2 I replaced were for the Liquid Crystals loosing their internal adhesion , That is, they looked like a silver watery display. remember we are heating that area to change the reflective angles, and those crystals do move.
Another thought, I might take the mirror connector and check at pin 1 (pin 2 is ground, pin 3 is +12V ignition switch). Pin 1 is from the backup light circuit. It supplies an additional +12v to the mirror when you put the car in reverse to 'shut off' the auto dimming feature. Something else to possibly check before calling it in need of replacement .
I took my Toyota in to the dealer when it's dimming mirror stopped working. I was really embarassed when the mechanic told all he had to do is remove parking permit that was covering the sensor! I guess I should have looked at it first, my wife put the permit on for her new job.