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Why is it that the heater only blows cold air
1991 Cadillac DeVille

Why is it that the heater only blows cold air

(1991 Cadillac DeVille)
Heater does not blow warm air
2 answers & 2 comments
Popular Answer
of GT Service Center on November 29, 2013
First make sure your coolant is full, then is your engine reaching normal operating temperature ( 180-200deg). Then check to see if the heater hoses are hot to the touch on both hoses. If that is all good then we move inside the car.
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on November 29, 2013
The temperature is up. What is inside to explore?
of GT Service Center on November 29, 2013
That's when we check your controls. But first we need to make sure the heater core is getting hot so we know it could be the controls. If the heater core is not heated by the coolant then it doesn't matter about the controls, we assume they are working until proof tells us otherwise.
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of GT Service Center on November 29, 2013
First make sure your coolant is full, then is your engine reaching normal operating temperature ( 180-200deg). Then check to see if the heater hoses are hot to the touch on both hoses. If that is all good then we move inside the car.
Sign in to reply
on November 29, 2013
The temperature is up. What is inside to explore?
of GT Service Center on November 29, 2013
That's when we check your controls. But first we need to make sure the heater core is getting hot so we know it could be the controls. If the heater core is not heated by the coolant then it doesn't matter about the controls, we assume they are working until proof tells us otherwise.
on November 29, 2013
Make sure your coolants level is good then check the temp at the inllet and outlet of theheater core hoses.could be low coolant level ;thermostat, clogged heater core or heater plenum concerns
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