Q: Why is my car blowing hot air and cold air at the same time?

asked by on

The other day i took out my HVAC system from the car trying to fix the LED screen, which I did not fix. After I but the system back into the car and took it for a drive the air started blowing hot and cold. It would blow hot air from the side vents towards the doors and the floor vents. It would also blow very cold from the center vents.

My car has 66000 miles.
My car has an automatic transmission.

The answer to this depends on whether you have switched on heating, cooling (A/C) or neither. In one scenario, for example, if you have not switched on the A/C system, but the A/C is running as confirmed by a visual check of the A/C compressor, and you are getting cool air obviously there is an electrical problem. The coincidental heating could be due to a blend door malfunction. If the only thing you did was remove electrical or electronic components, it would appear that you have an electrical malfunction in the controls. I recommend you request an HVAC diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. Why is my car blowing hot air and cold air at the same time?

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 have a 96 jeep Cherokee and I had just recently put in a new transmission. Today all of a sudden it didn't want to start and whe

It sounds like there are two issues, one is the hard starting and two is the harsh engagement. The hard starting obviously has to be resolved first. Although there are many causes of harsh engagement, it is possible that high...

Q: Where is the Heating A.C. door actuators2 Lesabre Custom with manual control.

It is attached to the HVAC assembly behind the glove box. Sometimes you can remove the glove box and access it and other times you will need to remove a good portion of the dash. This is determined on a...

Q: my battery kept draining until i bought a new alternator and battery. i have tightened the belt on the alternator but it still die

Hi there. The best way to diagnose why a battery would constantly drain is to review it's job and how it is recharged. The battery is responsible for powering all electrical systems until the vehicle is started. At this point,...

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...
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...
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.