Has anyone had there rear view mirror glass change into a what looks like blob? Can the glass on these mirror be changed out or would I have to buy awhole new unit? see attached pic. Posted this on Bimmerfest but no response so far...

 

What the hell happened to it?????

Look at Realoem.com for a replacement - it may show you glass and/or full unit...

The other forum mentioned is kind of dead by comparison.

 

From what I can tell its something that is common on the cars with the auto-dimming mirrors. Now just need to find a replacement...wonder if I can find one without auto-dimming....or even without Homelink since I think that is tied into the car security.

 

Do these mirrors dim by mechanically tilting the glass or electrically altering the reflectivity?

 

Some kind of electrochemical....I heard they cam sometimes leak out. I was giving two options, 1) have an Glass shop cut out a glass to fit over it so I don't loose the homelink/security or buy a replacement (cheapest so far is $300+). The Dealers have it for...well...we know that song.

 

Looks like the mirror has had 12v though it. The Auto-dimming is known as electro-chromatic (EC). Sensors front and back compare light levels and apply 1.2v across the front and rear surfaces of the glass element causing the liquid in the sandwich to change colour. 12v is enough to boil the fluid, turning it into what looks like a black lava lamp.

You will neeed to find the source of the 12v or it will happen again to any replacement. If you have auto dimming outside mirrors too, this could be the likely source of the 12v as the 1.2v used to dim them is supplied from the interior mirror. If you've repolaced a mirror glass recently, check the connections.

Good luck