Skip the auto shop - Our mechanics make house calls

Q: Heater only works at high speeds

asked by on

My heater only works when I am going a constant high speed on the freeway.

A: If the blower fan is operational, then you ...

If the blower fan is operational, then you might have a clogged cabin air filter. The filter is located behind the glovebox and should be changed periodically, to ensure proper HVAC operation and air volume. If the blower is not operating, then the blower motor circuit and relay may need to be diagnosed. You may want to enlist the help of a mechanic, such as one from YourMechanic, who can check the air volume of your HVAC system, and diagnose and repair the low air issue.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: Heater is not warm enough

Hi, thanks for writing in. The temperature of your heater is going to depend on the circulation of the coolant, temperature of the engine, and the associated parts working correctly. The blend door actuators, level of coolant in the system,...

Q: Smoking a lot and oil in the intake manifold

Thank you for your question about your 2003 Jeep Liberty. An oily, water vapor laden mist continuously flows from the engine's PCV valve to the intake. In some engines, a significant amount of the oil vapors will condense back into...

Q: Car shutoff completely at 100 mph

Hello there. A few items may be causing the high speed shut off. The most common would be a fuel pump, fuel filter, low fuel pressure, or the rev limiter. This kind of issue can cause the vehicle to become...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...