: Rear view mirror auto dim...is it built in?

08-19-08, 11:16 PM
Just wondering if the auto dim feature of the rear view mirror is built into the mirror itself or if all the wires running to it have something to do with it...only reason I ask is there's a good deal on one on ebay that would go great in my project s10. Thanks.

08-19-08, 11:34 PM
I'm sure their is a power wire running to the mirror for the sensor and everything to work but I think the light sensor is built into the mirror. As long as you could get power to the mirror I would think it could work. Just need a pinout of the mirror harness.

08-20-08, 06:48 AM
Sometimes the side mirrors are connected for that feature, I am not sure if the center mirror is in charge or just reports light levels to another module. For years as a solo feature it was self contained.
If you are desperate I can do some checking. I think it should function by itself even if it isn't sending out signals for the side mirrors.

08-20-08, 12:34 PM
not that desperate....like I said it's a good deal, I'll pick it up if I can't find something else.....thanks guys.

08-20-08, 12:39 PM
I would much rather have it NOT auto-dim and give me the option to turn it on. Is it possible to switch it around?

08-20-08, 02:46 PM
Correct me if I'm wrong but isn't it just on or off. No sensors, you just don't notice it in the day time? If thats the case its probably just ran with a power wire. Unhook the one in your car and measure the voltages. Or just buy it and see if you can make it work, and if you can't sell it again.

08-20-08, 10:36 PM
^^prolly what I'll do

I would much rather have it NOT auto-dim and give me the option to turn it on. Is it possible to switch it around?

alot of people are like you....personally it's one of two options I can't do without in any new car I buy...that and climate control...

08-21-08, 02:04 AM
Now that I think about it. It probably isn't on all the time and if that is the case I'm sure it just works off the light sensor. Which would still just be a power wire to the mirror.

08-21-08, 07:52 AM
There is a forward facing sensor and a rear facing sensor. When the rear one has light and the front one doesn't the mirrors dim.
As I said, originally this was a self contained system, until they tied it to the side mirrors.
I am sure the mirror would work on its own with power and ground.
Most of them have a switch that lets you deactivate the feature, in fact I think all the newer ones do.