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Q: Air conditioner blows colder at idle and heater blows slightly warm.

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ac blows cool when driving but cold at idle and the heater blows slightly warm even after driving several miles. The engine coolant is full , one heater core hose is hot and the other is considerably warm, engine temp is normal . I have heard a loud pop inside the cab recently like the the blend door slaming shut a couple of times before this problem . Can u tell me how and what to check ? 2002 f150

My car has 100000 miles.
My car has an automatic transmission.

Hi there. A blend door could be stuck and causing the outside air to enter the cabin compartment. Check the blend doors to see if they are sealing shut. If they are not sealing shut, then check the actuator and make sure that its working. Most actuators can be vacuum or electronic. Replace the actuators if they are not working properly. If you need further assistance with your heating and air conditioning, then seek out a professional, such as one from Your Mechanic, to help you.

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