535i Climate Control Issue

[TireFryer]

I just bought a 1992 535i. The dash (face) vents and the rear seat vents only blow cold air. The defrost and feet blow hot. Are these a mechanical mechanism or is there an actuator that controls that? The ac and all the temp control and other climate stuff works. I’d just like to have hot air blowing on my face in the winter lol. Any help appreciated. Thanks!

[dannyzabolotny]

I just bought a 1992 535i. The dash (face) vents and the rear seat vents only blow cold air. The defrost and feet blow hot. Are these a mechanical mechanism or is there an actuator that controls that? The ac and all the temp control and other climate stuff works. I’d just like to have hot air blowing on my face in the winter lol. Any help appreciated. Thanks!

Have you moved the dial in the middle of the face vents to the warm setting? There should be a dial that has blue and red on it to adjust the face vent temps.

[TireFryer]

Have you moved the dial in the middle of the face vents to the warm setting? There should be a dial that has blue and red on it to adjust the face vent temps.

That’s controlled separately from the settings on the hvac unit? The middle slider just makes the air switch the the face, and the dial wheel changes the temperature?

[shogun]

owners handbook explains it in detail https://archive.org/details/BMWE34Manual see pages 46 - 52

[TireFryer]

Appreciate it

[TireFryer]

@shogun I tried the scroll wheel and it almost made the right center vent warm, The door vents and rear were still cold. I stumbled across one of your old threads about the stepper motor actuator breaking out of its mount or the scroll wheel potentiometer going bad. Looks Like I will have to dig into the dash and get at the actuator. Any tips for that?

Thanks

[shogun]

My info about the stepper motor is for the IHKA version. link for repair https://www.bimmerforums.com/forum/showthread.php?2450902-DIY-IHKA-mixer-flap-motor-mount-completely-broken
https://www.youtube.com/watch?v=2oTkwNHrpLQ
https://www.bimmerforums.com/forum/showthread.php?2399245-E34-E32-HVAC-Stratification-Stepper-Motor-Bracket-Repair
https://twrite.org/shogunnew/fixes/climate.html#Remounting_flap_actuator_motors_
SIB 64 01 89 IHKA - Stepper Motor Bracket Breakage 1989-10-01 GROUP 64 Heating & Air Conditioning B 64 01 89 Woodcliff Lake, NJ Technical Dept October 1989
This bulletin supersedes S.I. 64 01 89 (1814) dated February 1989. Additional repair
information and warranty information have been added.
Please remove and discard S.I. 64 01 89 (1814) dated February 1989 from your S.I.
binder.
SUBJECT: IHKA - Stepper Motor Bracket Breakage
MODEL: E32
Situation: You may receive a complaint from a customer that he is unable to regulate the temperature out of the center dash vents or that cold air blows out of one side and hot air out of the other.
This may be caused by a broken stepper motor bracket for one of the two center dash vent stepper motors.
Diagnostic Hint: As the motors can still operate no faults will be logged in the IHKA Control Unit. Removal of the radio allows for visual inspection of these brackets.
Repair Procedure: Replace the center housing portion (P/N 64 11 1 374 325) of the IHKA assembly. Removal of the IHKA assembly is required. Follow the procedures given in the workshop manual (Group 64) for its removal.
Note: Grease running out of the vent flap stepper motors can cause the plastic mounting area to become brittle, thereby increasing the possibility of the mounting area to break.Stepper motors with the manufacturing dates of 752 or higher have been improved to prevent this from occuring. Inspect the two vent flap stepper motors. If the production date (stamped next to the electrical connector) is 751 or lower, replace the motor. https://bmwrepairguide.com/sib/640189.pdf

[TireFryer]

That write up is beyond helpful. Tons of information and exactly what I needed. Thank you! I’ll dig into the car and see what I can find!