Auto-Dim Rearview Mirror

It appears that this feature no longer works in my 99 burb.My green LED to indicate that it is functioning is not illuminated.I have done what is says in the owner's manual and the service manual to turn the system on,but it does not work.I am getting power up to the mirror,have a good ground and getting power when the tranny is in reverse.Am I missing something to turn the system on?Any help to resolve this problem would be great.A new one is really expensive.(so what's new)Thanks

Chuck's

Before going crazy, see if the mirror is functioning. With the vehicle in PARK and key in RUN position, cover up the sensor in the back of the mirror with a rag or something. At the same time, shine a light into the front sensor. You should see the mirror darken. If you do not, press the on/off button and try again. Just because the LED is not illuminated does not necessarily mean that the mirror is not functioning. The bulb may just be burnt out.

True that the bulb could be burnt,but the owners manual proceedure does not match the Chevy service manual proceedure.Which do you call the on/off button?
chuck's

Personally, I do not like like this auto feature so I turned it off (permanently). To turn off/on, hold the TEMP button (right) for 15 seconds

15 seconds!!!!that is a big difference from what the owners and service manual state.Tried it this morning and the green LED came on.I will check to make sure that the mirrors will dim.Thanks for the info.

Chuck's
In the evening I tested the auto- dim system and is now functional.Thanks for the assistance.
Chuck's