wedge357

I'm 99.9% sure. You think it will open up when engined is turned off but it doesn't. I've tinkered with the W212 AC often enough, including removing the plastic baffle over the fresh air inlet leading to the squirrel cage fan. On those occasion where the AC was on Recirc when the engine was turned off the vent flap covering the inlet remained closed. Even if it opens hrs later there would be enough time for the molds and germs to multiply.

thefisch

I can verify that the recirc flap will remain closed when car is off on my w212 at least. I've seen it the flap closed when taking off the air box. Also, when I did the lysol procedures outlined here, the climate control would open and close the recirc flap on its own in order to reach the desired temp as quickly as possible. Even when the recirc red indicator was not on, the flap was closed. This is different from my past cars of other brands. With those, the recirc indicator lights up even when the climate control engaged recirc on its own.

wedge357

Yes on the above. I've been wondering why Mercedes don't have the Recirc light turn on every time the climate control auto closes the inlet flap? You hear the air flow changes when it engaged so you know its on Recirc mode but for some reason there is no visual indicator.

thefisch

I'd prefer it the way I am use to, but maybe I am not smart enough to figure out why it's better not having the recirc led on whenever the recirc flap is engaged. Maybe the recirc button is only meant for manual mode, not auto.

alanme123

My car had a really weird AC smell.. like bad smell before and I took it to the dealer. They did an A/C flush on it and it was fine afterwards. No more smell. But then they charge money for that and I wasn't that much of a car techie to figure out what went wrong..

woodlander

Thanks for the info all... I've just gotten small hints of a smell so far, so though it was just me....
Any chance there's a "preventative dose" or action - or is the "treatment" described here really it?
Also, do any of you use Battery Tenders (or similar product) to address any drain/strain 1 hour of fan use would have on a discharging battery?