For some reason, the heater on our 2011 Chevrolet Equinox 2LT (I4 engine) blows cold air when set to defrost mode regardless of the temperature setting. However, the heater works in any other mode. This is happening both at idle and while moving. Is this normal? If not, what might be the issue and how might it be fixed?

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    Can you tell if the A/C compressor kicks on when you put it to defrost mode? Also, have you tried it in bi-level mode (the mode before defrost which does defrost and feet)? If so, what's the outcome of that? I don't know if your vehicle has an auto-temperature module, or if it just has a heat dial which you set? Nov 18, 2014 at 9:49
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    Sounds to me like a problem with the flaps that direct the air within the heater ducts - although I'd expect the direction flaps to be after the temperature ones...
    – Nick C
    Nov 18, 2014 at 9:51
  • I was thinking the blend door as well @NickC. The auto temp units can do funky things, which is why the questions. Nov 18, 2014 at 12:42
  • Might be normal. I think I've seen this before. It's to help defog. Have you checked the manual?
    – ki9
    Oct 26, 2015 at 0:54
  • Oddly enough, I've looked at the manual and it doesn't seem to say anything about it.
    – bwDraco
    Oct 26, 2015 at 1:12

1 Answer 1


The reason this occurs is to take care of the humidity in the vehicle while your defroster is running. MANY older vehicles have this as a common function when your defroster comes on. It's odd though that the temperature setting doesn't change your AC temp. Chevy's 2011's were all CAN BUS computer controlled systems, it might just be a glitchy computer issue.

  • Many older vehicles? Are there new cars that don't use the A/C to help remove humidity on the defrost setting? I thought this was pretty standard now.
    – JPhi1618
    Oct 27, 2015 at 15:20
  • I worded that incorrectly. What I intended to say is that many older simpler systems would run cold air no matter the settings selected. Hence why i said it was odd that his newer vehicle wasn't bias to what settings were on.
    – cloudnyn3
    Oct 27, 2015 at 15:32

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