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Q: Heater puts out hot air when set 80 degrees or higher, cool air if set lower

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I've owned this truck since new. At 90,000 had cooling system complete flush and fill and again at 180,000. I was wondering if it's the air control flow valve under the dash passenger side

My car has 230000 miles.
My car has an automatic transmission.

Hello.

From what you describe it may be possible that the issue is with the AC control switch or the blend door actuator. These are the components that are responsible for controlling AC temperature.

If they have any issues the AC system may still blow air but the temperature may not be correct. Another thing I would look at is the heater control valve, in the engine bay, as this is the component that allows hot coolant into the heater core to provide warm air.

If you’re unable to pinpoint the issue, consider YourMechanic, as one of our mobile technicians can come diagnose the issue with your AC firsthand and help you fix it accordingly.

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