Skip the auto shop - Our mechanics make house calls

Q: Why does my air conditioner stop cooling when the car is on idle or at a stop in a traffic light?

asked by on

My mechanic recently informed me that my car air conditioner compressor was faulty, and it was subsequently replaced. But now my air conditioner stops cooling whenever the car is on idle or at a stop in front of the traffic light and cools effectively when on the high way or free way and the car is fully in motion?

My car has 120000 miles.
My car has an automatic transmission.

A: Hello. Was the A/C working properly before ...

Hello. Was the A/C working properly before you had the condenser replaced? Your previous mechanic was correct that the condenser was likely the source of the issues. Now that the condenser has been replaced, we know its working and can tell its the cooling fan that is failing to provide adequate air flow. You should turn your attention to the fans. They can fail in several ways including the fan clutch, fuse, and its main control module. You may also want to verify that the connections are clean, dry, and tight. The first step is to check and see if the fans are working at all, or if they have not been working this whole time. If the fan is not working at all, it or its motor should be replaced. If the fan is working intermittently then there will need to be more testing to determine what is causing it to only respond to certain signals.

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: How do I select a folder from a list when using a USB device?

When playing from a USB device, you can view a list of the folders, and then select which one you would like to play from. To do so, press the Tune-Scroll knob to view a list of the folders, then...

Q: Interior light won't turn off

If one of the lights inside the vehicle is not turning off, then there is likely a short in the wiring or switch for that light. As wiring problems can sometimes be hard to diagnose or detect, I would recommend...

Q: A/C blowing hot air after car battery dies

Hello, thanks for writing in. I have not seen an instance where just replacing the receiver drier has fixed any problems with this A/C alone. You may indeed have a problem with the condenser or compressor, as you mention. I...

Related articles

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...
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...
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...