Are the liquid crystal mirrors on the earlier SC's (92-96) self-dimming (with headlight sensors), or are they manually activated (pushing a button serves the same function as flipping the lever on a regular prismatic mirror.)?
I always assumed they were self-dimming, but looking at some detailed pics I can't seem to find the light sensors. Another interesting detail I noticed is they seem to have the same mirror mount as my '96 ES. If they're auto-dimming, I want one.
Note: I was looking at an SC300 mirror. The 400s may have had a better mirror.

 

Early SCs are push button dim. I believe later models have a sensor for autodiming. Someone here can probably tell you the year they made the switch.

 

I'v got a 92 SC400, the rear-view mirror dims with a push of a button. No auto dimming feature that I am aware of.

 

Auto dim was added in 1993 on the LS..so I would imagine 93 for the SC also.

 

I have a 93' SC w/ Maunal Push button dimmer!
No Auto dimmer on this model year!

 

I have a 95 w/push button dimmer. No auto dim here. Probably a 97+ feature.

 

I have two 93 SC400s and it push botton...

 

Thanks for the replies.
Any clues from where the mirror draws its power? I assume when the mirror is in the dimmed position, it's drawing a small current to darked the LC. So, a non-ignition switched power source such as a vanity mirror would be a bad place to tap, as if I parked my car at night and left it in night mode, it would drain my battery (I know its a very small drain, but nonetheless). The other problem is that my mirror mount screw is horribly stripped, so getting the old mirror off, while leaving the threads in the windshield mount intact for the new screw could be tricky.
Perhaps I'm better off trying to find a shop that will heat off my stock mirror, and glue on a universal mount. That way, I can use one of the newer Gentex mirrors with the auto-dim and compass (same mirror as 02+ES, 03 GX).

 

I think the change was done in '96 can someone with a '96 or newer please confirm?

 

They all have a push button to turn the feature on or off. What you want to look for is the tiny hole that gathers light (the sensor). This indicates that it is adaptive. The 96+ do have this. This part will cost you around $600 if you don't have it.

 

Yep, the auto-dimming models should have a pinhole on the mirror side (to detect glare) and another on the windshield side (to determine whether it's day or night). I know the part from Lexus will be much more than the universal-mount Gentex kit, which has more bells and whistles (compass, there's even a model that has a HomeLink transceiver).
The advantages I saw in the SC mirror were 1.) not having to heat off the old mirror from the windshield (I'm having trouble finding a shop willing to do this), 2.) I thought I might be able to find a unit pulled off a salvaged vehicle for cheap (TAP Recycling, perhaps). 3.) Very clean, OEM appearance
Downsides of the SC mirror:
1.)No compass/Homelink/etc
2.)I'm on my own to create a wiring harness, figure out where to tap power
3.) Price, availablity issues, if purchased new
Advantages of the Gentex:
1.) Readily available, the part is available for less than $150
2.) Comes with harness and schematics
Downsides
1.) Have to risk damaging windshield heating off old mirror mount

 

I have a 95 SC400 and it was not auto dimming, so i went with an aftermarket mirror with auto dimming and compass. Looks and works great, easy hookup since you already have the wires installed from exisiting mirror.

 

i have a 96 and it, in fact, IS auto dimming, so this must be the first year that they added it to the sc line (400 at least).

 

I've noticed that with my 93 car and the autodimming (newer) mirror, even with just two of the four wires hooked up and the switch to auto-dim, the mirror will darken. I'm still trying to find out what the other two wires are for. I called the lexus dealership, but the guy wasn't too willing to help (read not getting paid to do someone else's research). He said he would call me back, but 1 week later, nothing....
If anyone has a wiring diagram they could post for the newer, auto dimming mirror, it would be greatly appreciated.
We'll figure this out yet

 

did you use the oem mirror body or did you use the entire aftermarket mirror ...since it seems you can have any color as long as it's black