QuestionQUESTION: My AC works great so long as I clamp off the hose from the Heater valve. Also the HEATER VALVE HAS BEEN REPLACED but the IHKA is allowing it to pulse open when it is 100 deg outside! It is maddening. What sensors might fail and permit the heat to fight the AC in this car? I am about to replace the entire IHKA since this unit contains the cabin temp sensor as well as drives the heater valve. Any better ideas? Outside temperature sensor reads correctly on dash.
ANSWER: You don't state which model this is, but the heater valve SHOULD come on in at least some models.
If you have a multi-zone temperature, the AC drives the temperature down to the lowest of the two settings, then the heater is used to bring up the side that desires it a bit warmer.
Likewise, your system MAY use the heat to control the temperature to the set-point. Heat is much easier to control than "cold".
Are you certain the heater cycling is your issue? Perhaps you have another issue, such as low freon that keeps it from getting cool enough. Or the control baffles aren't opening/closing properly.
I'd check alternatives such as these before replacing our IHKA unit.
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QUESTION: 2000 323i. I am very certain the freon is good. The left center vent does blow slightly warmer than the
Right center. Outer vents are ice cold. The thumbwheel is rolled to full cold. Why should I get heat when I am requesting 59 degrees from the IHKA? I have read that the baffles
Can be reset by disconnecting the battery for 15 minutes. Then re-connect and try it after they reset their positions. Ideas?
AnswerI'm not familiar with the resetting of the baffles, but it makes sense.
Reading elsewhere that the IHKA is often replaced when the issues are elsewhere. Not sure what the IHKA is going to cost you, but might be worth an hour of BMW time to diagnose (~$150)
