Q: My fan keep running when ac is on

asked by on

When ac is off, my cooling fan works fine, sometime on and sometime off, and coolant temperature is optimal around 90 - 100 C. But when I turned AC on, the fan will keep running, causing my coolant temperature to drop low to around 70 -75 C and always stay there and never go above that no matter how. When I turned the AC off, then after like 1 min, the fan will also off, and coolant temperature is optimal again.

Is it normal? What may be the cause?

Thank you

My car has 41000 miles.
My car has an automatic transmission.

Seventy degrees C (160 degrees F) is too low for optimal engine efficiency and may cause oil contamination and reduced engine life. You will get lower gas mileage, too. The cause of the sub-normal temperature is the extended fan operation but the situation could be aggravated if you also have a stuck open thermostat. To obtain a diagnostic pinpointing the root cause(s), and thence the necessary repairs, the recommended service is an electrical circuit/component diagnostic. In the course of that, the mechanic will pinpoint the fault and get it repaired. 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?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My fan keep running when ac is on

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 hit a median with the front driver side tire and then my front passenger tire caved in

Hello, thank you for writing in. Hitting a curb can cause damage to the tire, rim, and axle. Evaluating the damage on the drivers front tires is the first step. The tire may be damaged. The rim may now be...

Q: I was told I need new ball joints when I got new tires but once the tires were put on the symptoms stopped why is that?

What you are describing sounds like a bad or worn out ball joint. A ball joint is designed to pivot through multiple planes. Of course, because the ball joint constantly pivots at different angles, it tends to wear out more...

Q: Battery is fine but car won't turn over?

Hello, thanks for writing in about your Ford Fiesta. You need to check to see if the clutch starter interlock switch is making contact. If the clutch switch is bad then you need to have it replaced. If you're unable...

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...