Skip the auto shop - Our mechanics make house calls

Q: Heater only works on high. Heat is not hot.

asked by on

Car takes awhile for the heater to blow hot air. It only works on high. The air is not that hot.
My car has an automatic transmission.

A: If your heater only blows when the setting ...

If your heater only blows when the setting is on high, this may suggest that you have a faulty blower motor resistor. The highest speed setting may still work because in most cars in the highest fan speed settings the current bypasses the blower motor resistor. In some cars, if the resistor is failed, the fan may stop working completely. Another reason a blower motor resistor may fail is when the blower motor has a mechanical problem or when a foreign object jams the blower motor fan blade and prevents it from spinning freely. This leads to increased current through the resistor and causes it to overheat and fail.

The lack of heat being generated by your system may indicate a faulty heater core. The [heater core]((https://www.yourmechanic.com/services/heater-is-not-working-inspection) is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant to heat the inside of the car with the help of the blower motor that blows the warm air through the vents inside the car. I would suggest having an expert from YourMechanic come to your location to diagnose your heating system.

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

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: Worried about a noise in the engine

Having an engine noise can be annoying and damaging over time. Did the noises start after having the oil and filter changed? I ask because there are some aftermarket oil filters which will cause pressure variations in the engine, creating...

Q: Front tire locking up

A locking front wheel can be catastrophic in many cases. Your vehicle may be experiencing failure in its ABS system. Also this can be a result of a ceased brake caliper. I would have a certified mechanic take a closer...

Q: Not knowing my audio negative and positive wire colors on rear left door

Try the yellow as positive and black as negative. This is what was used on the same vehicle but for the 2015 model. I do not have a 2016 diagram. If you want a second opinion on this, consider contacting...

Related articles

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.