When you say you "cleaned" the IHKA...what does that mean to you...because reading it gives no clue as to what may or could have happened? I'm not trying to sound like Hillary Clinton when asked about when she "cleaned" her server and she responded with...."like with a cloth?".
But does it mean you vacuumed it while installed, dusted it with a cloth, did you remove it and take it apart, did you spritz it with some type of cleaner while installed, or did you remove it and soak it over night?
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Since there are TWO defrost buttons and you didn't distinguish which one...part of the problem could be that you're pressing the RAPID DEFROST/DE-ICE button which has a preset to turn the blower to high and raise the temp setting to HEAT.
The regular defrost button allows you to use the AUTO setting (which can automatically select air speed and air temp based on how you have selected the AUTO settings)...or you can manually select air speed and air temp.
Without knowing which DEFROST button you are pressing, it's not clear on what to suggest or recommend because some of your issues may not really be issues...whereas some are (like the blown fuse):