Outside rear view mirrors defroster.
 

Hi,

How can I know if my car is equipped with the auto rear view mirrors defroster?
I tought it was a feature in all cars, but when I connect the rear window defroster nothing happens on the outside mirrors.
I've tried to consult the realoem page with my vin WB48771 but I can't find that info.

Thanks in advance for your answers.

Best regards:thumbup:

Couple quick quotes from another forum
As for finding out if your car has them (without using realoem.com), just turn the car on and let it sit for about 2mins. Then feel the surface of the mirror's glass. If it is warm/hot to the touch, they are heated. This works best when temps are in the 60's outside.

In addition
Turn on temp is quoted as anywhere from 50 to 68 F and below. I'd recommend temps below 50 for testing. They are not to difficult to retrofit on cars without them.

Seems they are temperature dependent

mirrors are temp dependant. I don't believe are tied to the switch

yes temp dependent. I have the exact same question for my 08 X3.. the glass is ICE COLD. Does not defrost anything.

Loooking at the manual it states they are controlled by outside temperature and its not a special feature as in its standard option.

Not sure why they don't work. Im gonna remove the glass and look at the back of it to see;

I did find this, but its for a E36.. http://www.bimmerforums.com/forum/sh...heated-mirrors

I think they might be temp dependent but with rear defrost turned on.

yes they are. I just removed my mirror glass and the power leads run to it. Checked for voltage and its there when defrost is on, 12V.

Mirror glass measures 130ohm resistance.

Not sure why the things dont defrost anything though?

That's why. I have 2 euro mirrors on my workbench right now and one measures about 8.6 ohms and heats up nicely, the other about 57 ohms and does not. I was going to try to stitch the grid when I had some time haven't gotten around to it.

Hmm, id be curious to know if your successful with this? Because I don't see much behind the glass, its pretty much all the plastic backing plate.

I found this thread; Fixing E36 Heated Mirrors . . . DIY! | BMW E36 Blog

But the X3 mirror backs don't have access to the solder runs like they are shown there. So I don't know how i can repair the grid. How did you plan to even access it?

Keep me updated if you can fix it cause i'd love to fix mine!!

Sorry, I was talking X5 which seems to be a bit different and lots of the grid is exposed but I am still going to try to get the backing off to be able to work on it better. The guy on the link you posted is apparently repairing a place where the grid got rubbed through by the attaching bracket, not sure I'm going to be so lucky.