A very minor issue, but pointed out to the mechanic that while my headlights work just fine, the auto mode does not function. Not a problem because even I can remember a time that when it began to get dark, you turned on the lights. However, I do like things to work. Mechanic suggest that this function was handled by a sensor in the rear-view mirror. and, maybe I should just get a new mirror. Upon that news I noticed the automatic dimming feature of the mirror does not work either. Anyone have any idea about this. Not as exciting as a transmission leaking 4 qts. a day or an engine falling out, but nevertheless something to fix. thank you.

 

You should be glad it's not as "exciting" as an engine falling out.

The sensor is indeed in the back of the mirror unit. You might try cleaning it first with a q-tip and some cleaner. Otherwise it likely means a new rearview mirror in your shopping bag. Used ones do show up on eBay.

 

Oh, this evening I learned that the other function of the mirror is indeed working. The green light is on, so electrical service to the unit is intact. I'll clean the sensor and start looking for a new mirror, which is I'll admit, not at the top of my list of things I need. Had the power steering pump and a hose replaced today.

 

Do you have a gold mushroom cloud in the mirror? If so the fluid pack in the mirror has leaked. Search for a thread on rear view mirrors, there is a place that will rebuild them for much less then the cost of a new mirror. It's on my long list of things to do. Be careful if it's leaked it's an acid.

 

And a very nasty and corrosive acid at that. On the Lexus forum I used to frequent when we had Lexus SUVs, that leaking mirror fluid was called "dragon's blood"....