Skip the auto shop - Our mechanics make house calls

Q: The front heater works only at high RPMs and the back only blows cold air

asked by on

My vehicle has an issue with heating. Actually, there are two separate heaters that are controlled separately. One is in the front and the other at the back. The back one isn't toatally unresponsive, but it doesn't heat just blows cold air. Whereas, the front works when the RPM is about 2500. Please give me some suggestions. Thanks.

A: There are two distinct possibilities: there...

There are two distinct possibilities: there is either no warm coolant to the rear heater core or a blend air flap is permanently in the cool air position. With no warm coolant to the heater core there will be no way to get the air in the hot air circuit. If the blend door is not moving in the rear climate control box, then air is only fed through the cool air side and not the warm air side.

A temperature check of the rear heater core will determine if coolant is being circulated through the core, and an inspection of the blend air flap and control on the rear climate box will determine if air being drawn through the warm air circuit. You may want to enlist the help of a mechanic, such as one from YourMechanic, who can diagnose and correct the rear heater circuit.

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: I replaced new fuel pump and filter and ran good for two days and now it won't start

The fuel pressure should be checked to see if the new fuel pump failed. If pressure is below 40 psi when the key is turned on then replace the fuel pump and filter. When the tank is out you should...

Q: My air conditioner blows warm when idle, looses coolant and starts to overheat.

Hi! I have a couple of thoughts that may help you sort out the issues with your Explorer. There may be separate root causes of the issues with the air conditioning system and the cooling system. The first thing...

Q: My car will not start.

Hi there: If you're hearing a noise coming from the engine when you press the throttle, it's more likely an issue with the throttle cable, throttle control module or the throttle body that is causing the stalling and no starting...

Related articles

P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.
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.