Side doors on the blower motor housing

[Mless5]

When do doors on both side of the plastic cage are supposed to be opened and closed? What operates them and under what conditions? 1990 535.

Thanks.

[moroza]

The climate control module (IHKR) closes them a few seconds after the vehicle is shut off, and opens them when it starts up again. They are also closed when Recirculation is engaged. Failure to do the former results in a path for mice to get in.

[danespann]

Some cars have individual motors on each door. Some have one motor on the driver's side and a cable going across to actuate the passenger door. I think my 90 535 is the single motor setup with the cable.

[Mless5]

Thank you. It appears to be that mine are shut permanently, but there is an issue with recirculate button.
Should recirculate button control aux fan at all? My recirculate button does not light up, but it clearly controls aux fan up front. Super weird.

[shogun]

when you switch to recirculation (even when aircon is off), automatically the AC starts and of course the aux fan in low speed, this is to keep humidity under control.

[danespann]

Thank you. It appears to be that mine are shut permanently, but there is an issue with recirculate button.
Should recirculate button control aux fan at all? Mine recirculate button does not light up, but it clearly controls aux fan up front. Super weird.

That's normal, as engaging recirc always engages ac as well.
I've had a 89 535 where the ac recirc door motor was seized and never opened the vents. That meant on heat, there was very little airflow. Simply forced the doors open in the winter on that car. Not a proper solution but it was a beater anyway.

[cirrusblau]

I have an IHKA system on both my E34 and E32. Both of them have open doors when the car is off and closes when you turn on the engine or switch to key position 2. @Shogun, is this normal in your experience? My cars are JP spec too.

[shogun]

yes, this is normal, I have a German language training manual IHKA E32, in section 5.12 page 44 it shows http://www.e38.org/e32/klimaautomatik.pdf
Defrostlauflauf nach Ausschalten der Zuendung
die verschiedenen Luftaustrittsklappen werden mit Schrittmotoren betaetigt. Da keine Rueckfuehrpotentiometer verwendet werden, wird jede Klappenposition durch Speicherung der einzelnen Schritte bestimmt. Diese vorherigen Klappenpositionen bleiben 1 Minute nach Ausschalten der Zuendung gespeichert, danach wird aus Funktions- und Justagegruenden die Klappenstellung Defrost eingestellt. Erst nach circa 2 Minuten ist das Steuergeraet stromlos und damit funktionsunfaehig. Folgenden Klappenstellungen ergeben sich:
Fussraum-, Fondraumheizungs-, Fondraumbelueftungs-, Belueftungs- und Umluftklappen zu
Schichtungsklappen warm
Entfrosterklappen auf
Frischluftklappen auf
Geblaese aus

use deepl translate to translate to your favorite language

Also interesting is on page 41 Eichlauf nach Anklemmen der Batterie, = calibration run after reconnecting the battery
re-type the text if interested and use deepl translate

That it closes when ignition is switched on, is mentioned in section 5.11 Kaltstartverriegelung

[iberiadust]

Hello.

My ihka is not opening ANY flaps. All is closed all the time.
I changed the module with no difference after that. Next would the panel itself right?
sword works fine- all speeds works on the blower. Blower itself is new. Hmm
its the push button one with air con.

thank you!

[shogun]

probably the stepper motor is defective or the bowden cable broken, see here the details of the IHKA system , #7 outside air flaps http://bmwe32.masscom.net/johan/ihka/ihka.html
here you see the bowden cable which goes from left side to right side flap http://bmwe32.masscom.net/johan/ihka/temp_sensors_3.jpg

[iberiadust]

The cable is ok. I looked at it when changing the blower itself.

When both sides of the panel where undone under. I can see a few of the stepper motors and they just don’t do anything when changing settings.

Ill try the panel itself. ��*♀️

[iberiadust]

Hello.

I swapped a panel from a 750iL with UAC.
All flaps work now and car is getting nice and warm.
The flow could be better. I’m thinking to check the cabin filter if the 6cyl cars had one?! Maybe it’s clogged. Hmm