Side mirror heating when NOT COLD???

[robnitro]

I've read a few threads but nothing conclusive on this. Tried the suggestions but it's all mythology, cause BMW is like that with some things....

How do I get the side mirror heating to work when it's NOT cold outside?
This morning was a foggy sticky time, with the mirrors fogging up.

I tried rear defroster button, of course nothing.
I put the fan on defrost mode, nothing.

Book just says mirrors come on when it's cold. Yeah BMW, how about when it's humid and foggy?

No, in a "luxury" "advanced" car I have to wipe the mirrors during my commute because their idea of automatic is stupid.

[Qsilver7]

The exterior side mirrors operate on an interval based on ambient temperature. There is no on/off button.

This design does work...like in the scenario you identified. If the conditions are foggy or humid...the mirrors should be cleared by the heating of the mirror glass...even when the ambient temps aren't actually "cold". When you touched the mirror glass...was it ever warm? If not, perhaps the heating elements have burnt out and the feature isn't working?

The chart below was from the e38/e39/e53 era...but like a lot of things...BMW doesn't stray much from a design principle unless there's an issue that requires change or an update. So the e70 heated mirror interval is probably the same or something close to the chart below. You can search through the www.newtis.info website to see if you can find a specific chart or info for the e70:

[ard]

Looks similar...https://www.newtis.info/tisv2/a/en/e...irrors/XJnSfaZ


Run a wire to the ambient air sensor wires, with a switch- open the one leg and it should go to -40. That will kick on the mirror element....

[robnitro]

Yeah so in the summer foggy days about 5% heating which is useless. They do work, winter deiced fine.

Opening the switch will do that and also make an annoying i drive warning.

Sometimes I really hate bmw. I'm dreading the airbag recall too... Too much sensitive stuff to go bad. Engine wise and suspension, I love the car though.

[josiahg52]

Originally Posted by robnitro

Yeah so in the summer foggy days about 5% heating which is useless. They do work, winter deiced fine.

Opening the switch will do that and also make an annoying i drive warning.

Sometimes I really hate bmw. I'm dreading the airbag recall too... Too much sensitive stuff to go bad. Engine wise and suspension, I love the car though.

Well, mine seem to work in those conditions but exact conditions vary so maybe you're in some perfect scenario where it just doesn't.

I, too, was concerned about the airbag recalls - both of mine were replaced - but I had a talk with rhe advisor and the tech before hand, explained my concerns and stated my expectations and was successful. I have observed no issues over the past few months and several thousand miles.

[Nanniepoo]

Maybe this will be useful, maybe not, considering it's for a different car. But the i3 had a foggy side mirror this morning. As I was leaving I was curious if it would "fix" itself or not because all I knew about the heated mirrors was they worked in cold temps. However after a few minutes of being impatient I decided to kick on the rear defogger, and about a minute later the mirror cleared up.


Option 1, side mirror defogger kicked on with the rear defogger and it was solved in about a minute.
Option 2, rear defogger did nothing and it was just a timing coincidence, side defogger was already working on it, and it took ~4 min or so to defog the side mirror.


Regardless, you didn't mention how long you waited. Whether option 1 or option 2 was the situation, it still took upwards of a minute, possibly up to 5 to work. Any chance you just didn't give it enough time?

[robnitro]

I'll try rear defogger again earlier but the frustration is that it's not documented fully so all we are doing is guessing while we have to get to work etc.
In an f series thread the joke was that you needed a special bmw cloth to clear fog from mirrors when it's not cold out.