Climate Control / demister full fan speed

[Skier1]

The problem I have is with the climate control. When the windscreen is fogging up inside I hit the defrost button and the fan automatically goes to full speed. If you go to turn the fan down it automatically cuts the defrost function out.I know this is probably a safety feature to send full fan speed to demist the window but it is extremely annoying to be on full speed all the time on the defrost function.The fan really only needs to be on a slow fan speed to prevent continued fogging of the screen.Is this a normal feature ? can it be recoded or something done so as you can choose your own fan speed ? or is this just a annoying feature we all have to live with .

[Sbjkmtce]

Unfortunately yes

[motordavid]

Skip that 'power blower feature' if you want to: hit the snowflake A/C button, adjust the air direction(s) as you wish, (up on windscreen button for exp), and adjust blower level and temp as you want.

'Manual' method but does well, if windshield isn't covered in inches of frozen stuff...
GL, mD

[Qsilver7]

Originally Posted by Skier1

When I hit the defrost button...the fan automatically goes to full speed...fan really only needs to be on a slow fan speed to prevent continued fogging of the screen. ... Is this a normal feature...or is this just a annoying feature we all have to live with?

The answer to you both is no...you don't have to "live with this" (ditto Motordavid). You're suffering from "operator error"...in that you have a misunderstanding of the features of the IHKA control panel (and owners manual).

The IHKA Control panel has a pre-programmed RAPID DEFROST/DE-ICE button (which you seem to be using for normal control to prevent condensation build up on the windshield & glass)... And a regular air distribution button that allows you to direct air toward the windshield & windows...as well as choosing your own fan speed & air temp (or AUTO air temp & fan speed). And if the ambient temps are high enough...and the cabin needs to be de-humidified...then also press the A/C (snowflake) button. This is how to maintain "defrost" that is not a pre-programmed setting.

The IHKA has 4 air direction buttons along the left side:

• Upper vents (aka - defrost/demist with normal air temp & fan speed control)
• Dash vents (can be tempered warmer/cooler than the TEMP setting on the IHKA by adjusting the stratified air temp dial in the middle of the dash's center vent....see illustration below)
• Floor vents
• AUTO

(air distribution that can be chosen manually using the upper 3 air direction buttons on the IHKA control module)




(this is an e38 IHKA which has extra buttons for redundant passenger control...but the button icons & functions are the same as the e39/e46/e53)



(e39 & e53 IHKA: rapid defrost & regular air distribution buttons work the same as e38 IHKA pictured above)

[Skier1]

Awesome, thanks for the information and feedback.

[Qsilver7]