AC / heat issue

nadaclue · 08-28-2020, 08:16 AM

Hello everyone,
I'm hoping someone might have some insight since I haven't found any decent leads/answers.

I took my '03 3.0i in for a non-functioning AC that would only blow hot. The independent shop found it was the compressor and replaced it, no problem. However, even though it was properly circulating through the AC system, it wasn't blowing cold air.

So the shop did some trouble shooting and have found that the heater box under the dash isn't working properly so it blows heat and AC at the same time. They blocked off the heater core and right now the AC works without issue.

That brings me to my question, does anyone have any idea how the heat/AC box works at diverting airflow from one to the other? When I look on RealOEM, there are solenoids that appear to operate airflaps. Am I going to have to rip out the whole dash to get to this thing to figure out what's going on? First I'll check the obvious like fuses, but I'm really hoping I don't have to pull the dash!

https://www.realoem.com/bmw/enUS/sho...diagId=64_1281

zgood4u · 08-28-2020, 01:45 PM

I had this exact thing happen to me about a month ago. My mechanic took a look at the box and determined (forgive my lack of knowledge as I'm paraphrasing) there are tabs on that box that control the flow had broken. He saved me a ton of money by epoxying the tabs back. So far so good.

08-28-2020, 08:16 AM	#1
nadaclue Private First Class 52 Rep 152 Posts Drives: Urban Green 2003 3.0 Join Date: Mar 2008 Location: Chicago iTrader: (0)	AC / heat issue Hello everyone, I'm hoping someone might have some insight since I haven't found any decent leads/answers. I took my '03 3.0i in for a non-functioning AC that would only blow hot. The independent shop found it was the compressor and replaced it, no problem. However, even though it was properly circulating through the AC system, it wasn't blowing cold air. So the shop did some trouble shooting and have found that the heater box under the dash isn't working properly so it blows heat and AC at the same time. They blocked off the heater core and right now the AC works without issue. That brings me to my question, does anyone have any idea how the heat/AC box works at diverting airflow from one to the other? When I look on RealOEM, there are solenoids that appear to operate airflaps. Am I going to have to rip out the whole dash to get to this thing to figure out what's going on? First I'll check the obvious like fuses, but I'm really hoping I don't have to pull the dash! https://www.realoem.com/bmw/enUS/sho...diagId=64_1281
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08-28-2020, 01:45 PM	#2
zgood4u Second Lieutenant 494 Rep 240 Posts Drives: 06 Z4MC BSM Join Date: Apr 2011 Location: Alpharetta,GA iTrader: (0)	I had this exact thing happen to me about a month ago. My mechanic took a look at the box and determined (forgive my lack of knowledge as I'm paraphrasing) there are tabs on that box that control the flow had broken. He saved me a ton of money by epoxying the tabs back. So far so good.
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