Thanks for the info. The explanation on how the mirror works on the last page was interesting and may help explain my mirror problem. The mirror in my 2000 Solara, which I'm using as a baseline, appears to be binary, either on or off. The behavior described in the excerpt from the TCH repair manual says that the TCH mirror is continuously variable, so the amount of dimming is continuously changing. Headlights at a distance are intense point sources, but may not put enough illumination into the sensor to the dim the mirror. The mirror does dim sufficiently if a car is within 50-100 feet of me, although it takes about five seconds.

I'm going to the dealership tomorrow to compare the behavior of my mirror with that of a new TCH off of the lot.

SciFi Guy — An addendum: Judging by the Repair Manual diagram, I think that the forward-pointing sensor may be recessed a bit, or covered by a light diffuser or lens, so as to control its directional sensitivity. Yes, it's continuously variable in its action.

Stan