HVAC control unit

1994 GMC SIERRA
200,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
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KEVNLKING
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The AC/heat control unit keeps flashing when turned on sometimes it stops. Is it the head unit or the blend door actuator?
Jun 22, 2018 at 8:23 AM
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STRAILER
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It is flashing is trying to tell you a code can you count the flashes?

Please let me know. Cheers, Ken
Jun 23, 2018 at 1:53 PM
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KEVNLKING
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What does this mean?
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Jun 24, 2018 at 3:23 PM
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STRAILER
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Thanks for the video! This usually means you have a mode actuator that is not working. Here is a guide to show you what you are in for when doing the job and the location of the actuator for your truck below:

https://www.2carpros.com/articles/replace-blend-door-motor

Check out the diagrams (below). Please let us know what happens.

Cheers, Ken
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Jun 25, 2018 at 11:13 AM
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KEVNLKING
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Is this considered manual or automatic controls?
Jul 1, 2018 at 10:05 PM
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STRAILER
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It says they are the same for either. Have you tried to replace the actuator?
Jul 2, 2018 at 11:55 AM
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KEVNLKING
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Not yet, they were asking me if my unit is manual or automatic which I think is manual.
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Jul 2, 2018 at 12:02 PM
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DANNY L
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Hello, I am Danny.

Your application/unit is manual. Hope that helps.
Jul 3, 2018 at 3:58 AM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.