Front heater only blowing cold air and no change in mode for vents

2010 GMC YUKON
136,500 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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KBALL318
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With the heater on full blast set to 90 degrees, I am only getting cold air out of the front vents. When selecting where you want the air to come from defrost, front, and flow. There is no switching between them. The rear heat blows hot air. I think it is my blended air control actuator, but I also know there are two more, one for the modes, one for the temperature and one to blend the air from each side. I just do not know which one could be the culprit.
Sep 25, 2018 at 3:32 PM
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ASEMASTER6371
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Good afternoon.

Yes, it sounds like the blend door has failed. It is odd that the mode door has failed as well but I will post the information.

Roy
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Sep 25, 2018 at 3:40 PM
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KBALL318
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Thank you Roy for the quick response, I will take a look tomorrow morning when I get off of work.
Sep 25, 2018 at 5:05 PM
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ASEMASTER6371
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Sounds like a plan.

Keep us updated.

Roy
Sep 25, 2018 at 5:13 PM
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KBALL318
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It turns out, the fuse was blown.
Sep 29, 2018 at 8:04 PM
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ASEMASTER6371
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That is even better. a simple repair.

Remember, fuses blow for a reason. It will blow again. Make sure you check the components for good clean tight connections.

Roy
Sep 30, 2018 at 4:30 AM
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KBALL318
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Will do and it was the HVAC IGN fuse that had blown.
Sep 30, 2018 at 7:00 AM
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ASEMASTER6371
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That is the one that feeds the control head. Make sure the connection at the control head is clean and tight.

Roy
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Sep 30, 2018 at 7:04 AM