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Q: Why does the heater

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The heater and air conditioning only blow high when driving 45mph and over. When sitting at idle and the dial is set at 4-6 the air coming out of the vents is very faint if any at all

My car has 86000 miles.
My car has an automatic transmission.

Hello. There are several components that can cause the blower motor to fail. Have you been having any other issues with the car? Start by checking the level of your coolant. The thermostat can also hinder the flow of coolant through the system. Both of which would cause the heating and cooling systems to malfunction. The second and possibly more critical issue is why the coolant is low. This means the cooling system is either leaking, or the engine is consuming the oil. If you do not see any visible signs of a leak, top off the coolant and keep an eye on the level. Check the coolant level in the radiator and overflow reservoir. Top off the coolant as needed and test the heating and A/C systems.

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