Skip the auto shop - Our mechanics make house calls

Q: Heater and fan not working

asked by on

The heater is not working and the fan only blows air on high.

A: Hello. There are several things that could ...

Hello. There are several things that could cause that heater to not work properly and the fan to only blow air on high. It is possible that you have a bad thermostat, which would cause the lack of heat. It is also possible that your heater control valve could be malfunctioning or that your heater core is going bad or is clogged. The most likely cause for the blower fan only blowing on high is that the blower motor resistor is malfunctioning. To determine the proper fix for your truck, a certified technician, such as one from YourMechanic, should diagnose your heater issue and make a recommendation for proper repairs to get your heater and fan working properly again.

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: My 2001 Honda Accord keeps overheating

This can be caused by a number of things such as low coolant levels, a faulty thermostat, a clogged radiator or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant...

Q: SUV parked for three years

Hi. Parking a vehicle for that long is never good. Things like wiring, starter, fuel pump, and transmission can all go bad from lack of use. In severe cases, engines do seize up from rusting internally due to lack of...

Q: My suburban has a gas leak but only leaks when someone turns the key on, other then that it doesn't leak at all. What could this b

The reason it leaks is the fuel pump is under pressure when you turn on the key and will pump the fuel out of where ever it is leaking. Do not drive it till the leak is found and fixed....

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...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...