Skip the auto shop - Our mechanics make house calls

Q: Why does the heater

asked by on

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.

A: Hello. There are several components that ca...

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: put key to start car goes dead leave in run position 2 min then car starts

Your vehicle may have an ignition switch that is not making a good internal contact. GM has had multiple major recalls pertaining to problems with the ignition switch. These recalls may relate to your problem. The only way to see...

Q: Coolant in oil

While coolant in the oil is usually sign of a blown head gasket, its possible intake seals have started to corrode and leak coolant into the crankcase. I would recommend a certified mechanic, like one from YourMechanic, do a cylinder...

Q: Oil Pressure Gauge

This light will usually come on when one of two things are happening. Either the motor is in fact low on oil or the oil pressure sending unit is not working properly and may be producing a faulty reading. I...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.