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Heater blows cold when set to hot and blows hot when set to cold??????

M

Markgp

New member
Hi, I have a 2006 GT with the dual auto climate control. Recently I noticed that it was not blowing hot air. So I checked the following:

1. The coolant level: looked good
2. The hoses entering and exiting the heater core. : Both were hot..
3. I checked the actuator that controls the heater flap and it seem to be operating properly.

So I tried to adjust the temperature up to 90 degrees and it continued to blow cool air with the car at running temperature. So I set the temperature to 60 degrees and it start blowing hot air?? If I then turn the AC on it will start blowing cold? What would make it work in reverse. When I set the temp to 60 it blows the air out of the front vents (Hot) if I set it to 90 it blow cold air down on the floor. So it seems to be sending the air to the right place, just the opposite temperature?

Any help would be appreciated?

Thanks!
 


thats a good one for sure. seems like the actuators are working backwards.

those newer cars act up when the battery terminals are corroded, un hook the battery, clean the terminals up good, wires and bat sides.


any chance you had the battery unhooked in the near past? sometimes unhooking the battery can sometimes make the actuators act up. some times taking the battery off for 30 minutes will clear them up because they should re set when they get power.
 
Also it may have started blowing hot on cold momentarily because the area where cool air is grabbed from was hot from the engine running, but should have cooled off after a bit. After you turned on the ac and it cooled, go back and try the first thing again and see if it was just temporary.
 
Hi, thank you for the advice. I appreciate your help. I think you are correct about pulling the heat from the Engine as now it only blows cold no matter the setting. I put in a new blend actuator just to make sure that the original one wasn't the issue and it had no positive effect. The actuator is definitely working. I physically moved the blend door by turning the knob with the actuator removed and it didn't seem to matter if it was open or closed as it still was pulling cold air. I double checked the hoses going in to the heater core and again both are hot. Is there another actuator that would effect the air flow through the core?
 
Update. . I had an air pocket in the heater core. Flushed the system and now everything is working great.
 
Glad you got it fixed. I would have mentioned bleeding the system but you mentioned: "The hoses entering and exiting the heater core. : Both were hot.."
 


Ironically both hoses were hot, I think both hoses were getting hot but not actually flowing through the core. When I disconnected the hoses, I actually filled up the core as it was nearly empty. For what ever reason the coolant would get hot on both lines. The coolant flush seemed to be the final trick. Thank you again for the help.
 
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