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Discussion Starter #1
I have searched this on 3 sites with no luck. Several people have had the issue but havent found a fix yet. soo here goes:

My A/C and Heat both work great, hot and cold just like it should. But temp control does not work so great. I set it at 60 degrees and it blows cold both driver and passenger side. But when i try to get heat i get very little if any temp change as i turn it up, till i get to 89 degrees. at 90 degrees both driver and passenger go full hot and will blast you out of the truck. I understand there is some actuator or module bad and getting no heat till 90 is selected is sort of a safety so that you can still get heat if needed. But its miserable trying to control the temp in the truck when all you have is full cold and full hot, nothing in between. Anybody had this issue and fixed it? any input would be appreciated. From what i have read on searches it probably is not the heat and air controller/selector in the dash. That has been tried by a couple of people with this issue with no luck. I manage to fix most issues that arise 95% of the time but this one has me stumped. :help
 

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Sounds like a blend door actuator.

Sent from my SPH-D700 using AutoGuide App
 

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i am having the same exact issue with my truck it only blows heat at 90 any less is ac.
 

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i had and have again sort of the same issue. more than likely it is the blend door/ actuator. right now i start out with the a/c blowing and then it kicks to heat all by itself. i changed the actuator a year or so ago. i can kick the air duct on the pass side by the console sometimes and it goes back to blowing cold again. i can turn the truck off and start back up and it works fine. damn grimlin running around in the dash! lol.
 

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Discussion Starter #5
i am having the same exact issue with my truck it only blows heat at 90 any less is ac.
Heads up. I pulled the fuse for hvac under the hood and let it set for ten minutes. reinstalled the fuse and started truck. I didn't touch anything for 3 minutes. Then with truck still running i took the rt side to 90 degrees and the lt side to 60 degrees. Let it set for a couple of minutes. Then reversed the settings. rt to 60 and lt to 90. let it set for a 3 minutes. Presto chango everything works fine.


Im not saying this is "the" way to reset the system, because i did similiar procedure 3 or 4 times before with no luck. All this seemed to start after i changed the batteries last year which seems to be a common problem. I just could not get a the system reset for some reason. Just kept trying and all is good now.
 

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The blend door actuator gets stuck when it isn't used over the summer, mine did it too last week. It shouldn't happen again untill next year.
 

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Heads up. I pulled the fuse for hvac under the hood and let it set for ten minutes. reinstalled the fuse and started truck. I didn't touch anything for 3 minutes. Then with truck still running i took the rt side to 90 degrees and the lt side to 60 degrees. Let it set for a couple of minutes. Then reversed the settings. rt to 60 and lt to 90. let it set for a 3 minutes. Presto chango everything works fine.


Im not saying this is "the" way to reset the system, because i did similiar procedure 3 or 4 times before with no luck. All this seemed to start after i changed the batteries last year which seems to be a common problem. I just could not get a the system reset for some reason. Just kept trying and all is good now.
My batteries are pretty old. Could old batteries be the cause. Im going to try the fuse method later today.
 

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Discussion Starter #8
My batteries are pretty old. Could old batteries be the cause. Im going to try the fuse method later today.
I believe the issue is common after changing batteries, or anytime you have them dissconected for whatever reason. It puts the system out of sync. Then when you pull the fuse and do the reset procedure it resyncs the actuators and everything works again as it should. I dont believe weak batteries would have anything to do with it.
 

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I believe the issue is common after changing batteries, or anytime you have them dissconected for whatever reason. It puts the system out of sync. Then when you pull the fuse and do the reset procedure it resyncs the actuators and everything works again as it should. I dont believe weak batteries would have anything to do with it.
Annother thing i notice this issue soon after my truck was flashed with efi.
 

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I have the same exact symptoms with my truck. I am going to try and reset it by pulling the HVAC fuse like you did. I will let you know what happens.
 

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Bump
 

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Fixed mine there is a factory service bulliton bad connection right side behind the cover in dash u remove after opening passenger door
 
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