Fresh Air

It's "intelligent," what else do you want?

Some design, jeeeez.

Makes me appreciate my "stupid" car.

It wouldn't be the first German car built without a fresh air blower option. It was a rather annoying habit of Audi a few years back.

What exactly are you talking about? Model? Year?

Juergen

THERMOTRONIC normally uses fresh air from the outside.

Have you already tried to switch-off everything (_auto_ buttons and _a/c_ button)? As at higher outside temperatures air-recirculation mode is activated automatically, in such a situation deactivate it then by pressing the air-recirculation mode button (car symbol with circular arrow inside, indicator lamp in the button lights if air-reciculation mode is active).

Now there should be no automatic cooling or heating (and no air-dehumidification) - you can control the amount of air coming in by pressing the buttons with the big fan symbol (increases airflow) and small fan symbol (decreases airflow). That should give you fresh air from the outside only, without any heating/cooling/air-dehumidification. And be sure to set the air distribution to the desired mode by using the two thumbwheels (around the _auto_ buttons) and to open the air vents by use of their thumbwheels (4 altogether).

Does that help?

Juergen

Indeed, my 1999 E430 (for example) defaults to fresh air unless I turn

Yes, of course. I should have said 'not-treated' fresh air.. ' Its a CLX 240

Certainly does.... I'll give it a try tomorrow. Thanks.

David.

Minor thing - did you mean CLK... ?

DAS

Yes - it was way after my bedtime....lol

David

Yes, that seemed to do the trick, That's with a red light showing on the AC OFF switch, and no Auto red lights.

(why didn't MB call it the AC ON switch, like everyone else?)

Those two Auto red lights seem to have a mind of their own. A simple press doesn't always extinguish them. A rotation seems to work.

There is also the word Auto on the blower speed display. That one goes off as you reduce the blower speed manually. Is that indicating the same information as the red lights in the 2 rotary switches?

I realise that with an automatic control system like this, you can't fiddle with the knobs and expect immediate results. It takes time to stabilize. Overall, it's a bit too smart IMHO.

Thanks for the response.

FWIW I have a CLK cab W208 (2001) with what i think is called ACC (auto climate control).

The red auto light go off -- IIRC -- when I fiddle with fan speed switch.

It seems you have a different arrangement. I think you have a newer generation as I have no knobs with lights.

DAS

Probably.

This is what the Thermotronic control panel looks like on mine