Blend door motor(s), HVAC controller...?? Air circulation not right

[jpilk99]

Hi All,

I am currently not having air flow through the "defroster" (top of the dash) nor are the passenger controls working; air only comes out at footwells regardless of setting on HVAC controller.

I read a few posts about the wrong temperature air coming out of the specific vents they're supposed to and learned a few things. I have been able to confirm that the actuator motors on both Driver and Passenger are working as they should. The damper doors both open and the 'AC vs fresh air' vent door work as well. I put in new filters at the damper doors.

It would seem to me that either my blend door motor on the passenger side is dead; or the HVAC controller is shot. Either could be the culprit, just not sure and am hoping to narrow it down before either buying another HVAC controller or taking out the dash to get the blend door motor(s).

When I select "Max AC", the button does not light up and nor does it go into Max AC mode. I can manually set the fan speed I want, and either fresh vs. AC air, but, when I select either dash or feet on the passenger side, the buttons do light up but the air ONLY comes out at the feet.

Driver's side works as it should, however, when I select the defrost button, the fans kick on to full speed, but, no air comes out the top of the dashboard at the base of the windshield.

Any ideas?

Thank you,

Jay

[psjr]

The "Max A/C" not lighting up may mean it needs some coding, but is separate from your other issue, which sounds like one of the two small 3-pin cables is unplugged from the back of the controller.

[jpilk99]

The "Max A/C" not lighting up may mean it needs some coding, but is separate from your other issue, which sounds like one of the two small 3-pin cables is unplugged from the back of the controller.

Thanks psjr. Just to be clear, the "controller" is the what I'm calling the "hvac controller" with all the fan speed settings, temp, direction, AC, etc. just below my radio?

Thanks,

Jay

[Qsilver7]

...Just to be clear, the "controller" is the what I'm calling the "hvac controller" with all the fan speed settings, temp, direction, AC, etc. just below my radio?

Thanks,

Jay

Just an FYI...that component's name is your IHKA control module.

[jpilk99]

I wonder, if by me disconnecting the IHKA control module has caused this problem ...sounds like I may hav to go get coded?

[acspecialists]

I replaced some push buttons in mine to fix some problems. I did not have to code it.

https://www.bimmerforums.com/forum/s...0#post29618860

Page 20 shows the photos of my control head apart and the switches I swapped.

[jpilk99]

Thanks!!! I'll give it a try

[jpilk99]

Gettin back to this thread that my control unit seems to be workin fine, (able to adjust fan speed up and down, temp settings, MAX AC etc), but, when I try and direct air to come out passenger vent, it just goes out to their feet. And when I try to use defrost, I can hear the internal air flow behind the dashboard changing ...but nothing comes out the top (defrost).

If I pull off the dashboard ...is there a way to test the blend door motors?

[Mayorchuck]

BMW software can tell you if the stepper motors/actuators are working properly.

[jpilk99]

Thanks Mayor. Bummin' that I don't have BMW software, nor do I know anyone - other than my mechanic who charges $100.

[Mayorchuck]

Not sure if you can get your hands on the blend motor or not. Looks like it's close to the passenger side cabin filter.

M35, X664


LH side of RH footwell

M35	Defroster flap motor
X664	Component connector (3-pin, black), Defroster flap motor

[psjr]

Did you take the IHKA out and check that everything is connected?

[jpilk99]

Did you take the IHKA out and check that everything is connected?

I did not. Will try that.