Skip the auto shop - Our mechanics make house calls

Q: Fan Motor running when a/c is on upon start up.

asked by on

I noticed yesterday upon starting the Yukon within a few seconds I could hear the fan motor running real fast. The a/c was on when started up. So today I started it with the a/c off. I could see the two fans were not turning when I turned on the a/c they started turning making the loud noise that fans make. Can you advise? Thanks, Kim

My car has 210000 miles.
My car has an automatic transmission.

It’s a normal condition for the fans to be running whenever the A/C is on. The fans need to be running when the A/C is on, because this is how the refrigerant is cooled down. The refrigerant passes through the condenser, which the fans pull air across similar to a radiator. If the fans didn’t cool down the refrigerant this way, the A/C pressure would get way to high, and could damage the system. If there is any sort of problem with the A/C operation, you can have a qualified professional, such as one from YourMechanic, inspect your entire A/C 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

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. Fan Motor running when a/c is on upon start up.

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: timing chain

Hi there. It is very difficult to give you an accurate estimate of how long it takes to replace a timing chain; as there are multiple variables to consider such as damage done to the chain, gears or other internal...

Q: None of my power window will go up or down. And I just replace the power window relay

Check the 20 amp power window circuit breaker in the engine compartment fuse box. If the circuit breaker is sending power to the relay then the main power window switch will need to be checked to see if it is...

Q: whining noise front of engine, EVAP and temperature control

Hello, thank you for writing in. The first two symptoms may be related. Finding a leak in the EVAP system will take some time and focus. If the noise goes away after fixing the leak, then we know we can...

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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...