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heater wont blow hot air inside cabin

Blackout51

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I just flushed the cooling system and changed radiator and thermostat with housing and now I turn heater on high hot and it comes out full blast but is only slightly warm not hot, any ideas? Also when it runs both heater hoses get the same temp so theres no clog in the Heater core
 


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drdoom

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Is the blend door working properly?
 








crunchie_frog

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Sounds like you may have knocked your vacuum loose to the heater control valve.
 




koda2000

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crunchie_frog

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The heater control valve is in the engine compartment on one of the coolant hoses going into the heater core (look on passenger side near the fire wall). There is a vacuum hose that connects to the valve. I believe the valve is closed without vacuum and if that is the case then no coolant (or very little) will flow into the heater core to provide heat. The original vacuum connection for this comes from the front of the engine compartment in front of the intake. It goes from there into a reservoir under the passenger side fender well and the reservoir holds vacuum to the AC/heater controls and ultimately goes inside where the heater and ac controls are. This vacuum moves all the doors/panels for the vents and ducts and also controls the heater control valve.

Also, I am assuming your engine is heating up to normal temperatures?
 




Blackout51

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The heater control valve is in the engine compartment on one of the coolant hoses going into the heater core (look on passenger side near the fire wall). There is a vacuum hose that connects to the valve. I believe the valve is closed without vacuum and if that is the case then no coolant (or very little) will flow into the heater core to provide heat. The original vacuum connection for this comes from the front of the engine compartment in front of the intake. It goes from there into a reservoir under the passenger side fender well and the reservoir holds vacuum to the AC/heater controls and ultimately goes inside where the heater and ac controls are. This vacuum moves all the doors/panels for the vents and ducts and also controls the heater control valve.

Also, I am assuming your engine is heating up to normal temperatures?

Is it a very small hard plastic line that runs over the passenger inner fender between the reservoirs and the motor? And yes the engine heats up to normal temps, I watch it on my code reader and it hits 190-194
 




crunchie_frog

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Yes, that sounds like it. The point is, you can check to see if you have vacuum to your heater control valve. If you were working in the engine compartment you could have disconnected the vacuum connection to the heater valve. If you broke plastic hose, all your ducts should go to defrost
 




Blackout51

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Yes, that sounds like it. The point is, you can check to see if you have vacuum to your heater control valve. If you were working in the engine compartment you could have disconnected the vacuum connection to the heater valve. If you broke plastic hose, all your ducts should go to defrost
I do know that I was looking for an electrical connector in there and accidentally did break that small line A's hear something that sounded like a long slow pressure release coming from somewhere then it stopped, I tried to tape the line back together, it was right by the elbow by the reservoir where I broke it ,but all my different ducts work just the heat doesn't, I can switch from floor to defrost to straight at me vents
 




crunchie_frog

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Also, I am not sure that vacuum closes the valve, I was just thinking it was something easily checked
 




Blackout51

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Also, I am not sure that vacuum closes the valve, I was just thinking it was something easily checked

I will have to follow that like a check it's connection points when I check the blend door sometime this weekend
 




koda2000

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you cannot tape the broken line and have it hold vacuum. the long slow pressure release you heard was the vacuum being released from the vacuum ball/reservoir in the passenger side front fender. you can purchase replacement vacuum line and connectors at any auto parts store. take the old piece for size comparison. as far as the heater control valve, some years had them and so don't. if you do have one, you can actually see the linkage, which comes out the bottom, move/work. if you have a vacuum leak, even a small one, lots of HVAC stuff will not work correctly.
 




Hatcher686

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Your thermostat went out. Its a very cheap part and easy fix. You will need to drain your antifreeze to change it out. Once you replace the thermostat you will have heat.
 




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