Heizung/Klima: StepperMotors

[Beumers]

Hi all.
A few years ago I removed the dashboard in order to repair the mounting from the 2 steppermotors on top of the hot and cold air regulator.
For some time now the front window airducts keep blowing hot air no matter what. So I want to fix that.
I fond a secondhand regulator and want to exchange the upper part of the regulator. In order to check the free play of the mechanism from the airvalve axels I want to remove the steppermotors. If I put them back on, do I have to position the axels in exactly the same position to prevent the steppermotors from demaging the housing.

Greetings Henk.

[Chioliny]

Hello,

no, not exactly, that's what the controller does. There are no potentiometers on the stepper, this is done by the IHKA controller. This recognizes the position of the flaps.

Best regards Chio.

[Beumers]

Thanks.
That's very helpfull.
Henk.

[Beumers]

Hello all.
Reading alot of links on this site I came to the conclusion maybe the solution to the problem is not to exchange the steppermotors which were broken in the past.
If I'm not mistaken the hot air is controlled by one motor operating both the airducts (red in the drawings). Ergo this cicuit does not belong to the separated system for driver and passinger.
So the blue circuit is controlled by the blue motors. 4 in total.
Even if the airco is working the air from the red circuit is as hot as it get's. I had these openings closed with tape last summer. How can I check if the watervalves are still working allthough it would be odd they both go faulty at the same time apart from the fact they seem to blong to the separate system.
Is there a separate control unit responsable for the red circuit in my drawings? I wasn't able to open all links on the site I was on. I could not find out if there is such a system.

Thanks for now. Henk.

No need to reply in English.

[Chioliny]

Hallo Henk.

hier mal ein Link zu den Heizventilen  Klich Mich

und hier die Komponenten der Klima  Klick Hier

Mit dieser Info solltest Du alle Probleme Lösen können!

Ach ja, hier ist noch die Arbeitsanweisung von BMW  Klick hier

Grüße Chio.

[Beumers]

Hi Chio.
Thanks. A few of the articles I read allready. I know there are alot on the forum. But some of the links will not open in my browser. (Maybe they are renamed but more likely I have some privacy settings blokking them. I'll find out.)
It's a complicated problem. There are a number of symptoms and it's difficult to pinpoint the separate problems. I think at least one of the watervalves is not operating correctly. But apart from that the plaps from the airducts to the front window do not close. I didn't had the time to check the stepermotor as I had to store my car for the nex 3 month because of some stupid oldtimer regulation in Holland for a few years now.
So I have 3 month time to get to the bottom of the problem. I try to find some info on the control unit behind the sword. I can imaging if the control unit misbehaves the steppermotors will get the wrong info.
These electrical problems start to wear me out.
Thanks again.
Great forum.