Why Does My Car Fan Keep Running After I Turn It Off?

We frequently face a lot of difficulties inside our car, but this is quite confusing Why Does My Car Fan Keep Running After I Turn It Off?  The fact that your fan was always running confused a number of car owners. What can be the reason and solution to this issue?

The fan running for a short time, like a few minutes, to keep your engine cool after your car is switched off is actually fine. Running the fan constantly for an extended period of time, however, may be a sign of damage, relay issues, overheating, a stuck cooling fan temperature switch, or a different issue with the internal parts.

Therefore, we will talk about the issues, and we have some excellent tips waiting for you below. Let’s have a look at the article to troubleshoot the fan issue.

What does it mean if the engine fan in my car stays on after I turn off the ignition?

  • The fact that fan is running even when the car off indicates that it’s keeping your engine cool. 
  • However, if the fan keeps running, check for interior vehicle difficulties because this is a sign that your car is defective, mistreated, or overheated.

Possible reasons a cooling fan stays on too long after turning off

fan still running when car is off
  • Defective PCM or ECU
  • Overheated
  • Blocked radiator
  • Incorrect thermostat housing
  • Low radiator hoses
  • Faulty temperature sensor
  • Straight wiring
  • Relay failure for a cooling fan
  • Temperature/low coolant level sensor
  • Leaks in the heater core, thermostat housing, or water pump
  • The corroded coolant bypass pipe
  • Electrical cables are shorted.

Can low coolant cause your fan to stay on?

  • The ECU indicates your car fan keeps working even after shutting off the engine since car coolant is still heated.
  • A low coolant level means your coolant fan will have to work harder to maintain a normal operating temperature for the engine.
  • So make sure to regularly inspect the engine bay’s coolant expansion tank.
  • A stuck relay that is keeping the circuit closed is another reason why your air conditioner’s fan won’t shut off.

How do I know if my cooling fan relay is bad?

Usually, we notice some signals that indicate your cooling fan relay is bad. Let’s have a look at the signs of vehicle’s bad situation.

  • The engine is too hot.
  • Your cooling fan either won’t turn on or keeps running.
  • Warning sign or light
  • Bad AC performance.
  • Relay swapping
  • The vehicle is making an odd noise.
  • Measuring the resistance of relay coil.
  • Ramping up the relay.

How long should a car’s fan continue to run when the engine is shut off?

  • The automobile fan shouldn’t run for more than two to three minutes, and if it does, the sensor in the car is probably malfunctioning.
  • Occasionally, especially during the summer, the engine might run for five minutes to cool down. It’s magnificent, dear!

When should your cooling fan turn on?

  • The temperature switch setting that controls power to the fan has no bearing on when the electric cooling fan runs.
  • There are two cooling fans: one is used to cool your engine, and the other is used to cool the air conditioning system.
  • The fan runs at a typical 70° to 80°.
  • Around 200 degrees Fahrenheit should cause your radiator fan to turn on.
  • After about 15-20 minutes of idle time after a cold start.
  • Basically, the fan specific to the AC system will run anytime the AC system cycles on. For this reason, you must turn off the AC before monitoring your cooling fan.

Should radiator fan be running all time?

radiator fan keeps running when car is off
  • Your radiator fan doesn’t need to be working continuously.
  • Temperature impacts how radiator fans operate.
  • We should keep that engine temperature at an ideal level when maximum efficiency is attained and cut-in and cut-out are connected.
  • Since there is no way to transfer the heat from metal engine components to radiator, coolant trapped in the heads might boil.
  • The fan is connected to a sensor that monitors the radiator’s cooling capacity. If the temperature in radiator starts to rise, the sensor will signal your fan to turn it on.

Can you drive with a bad radiator fan?

  • Yes, you can continue to drive even if your radiator cooling fan breaks.
  • However, it’s not suggested to drive a car without a functioning radiator cooling fan, as it will heat up quickly and perhaps develop a water pump issue if the fan belt breaks.

Do both cooling fans run at the same time?

  • Except when the car is hot, they each operate independently. But later on, they start to work together.
  • But normally, when engine reaches a specific temperature, only one cooling fan operates. The second cooling fan is intended to operate when air conditioner is turned on, increasing airflow through radiator.
  • Additionally, one fan will turn on if parking lights are on and temperature is 212 degrees or higher, and both fans will turn on when temperature is 230 degrees. A fan will also turn on if the AC is on.

How do you fix a cooling fan that keeps running?

  • Turn your fan off by unplugging battery cables.
  • Replace your defective fan relay with a functional one to test the fan.
  • Use a digital multimeter to test the car coolant fan relay’s performance.
  • Check for potential leaks and insufficient coolant levels.
  • Verify the wires’ consistency.
  • The cooling system and radiators should be cleaned.
  • Checking the temperature of coolant pressure sensor as well as the level of freon.
  • trying to look at the EC.

How much does it cost to replace a car fan?

  • Depending on make or model, a replacement fan will normally cost between $300 – $400.
  • Also, you can estimate investing approximately $80 to $150 for a replacement radiator fan.

FAQ

1. Why does it sound like a fan is running when my car is off?

Typically, the fan keeps running as the engine cools, but some cars have systems to continue running even when the engine cooling fan is off. It’s perfectly normal, but if you find it running for a long time, detect the trouble inside your car.

2. Why is the radiator fan always on?

If a radiator fan keeps running long after engine has been turned off, it is frequently caused by a defective cooling fan relay or electrical control unit, and radiator must be cleaned. Overheating or a defective chip might also be to blame for such situation.

3. Why does my radiator fan keep turning for about 10 minutes after I turn off the engine (Mitsubishi diesel)?

Usually, fan runs to keep things cool, but if car fan is turned on for 10 minutes, Mitsubishi diesel engine electric fan may continue to operate even if the air conditioner is not functioning. This happens because there is a significant shortage of coolant. In order to avoid running out of coolant, make sure to check the level.

4. Why does my Audi A3 fan stay on after the engine is off?

Almost all car fans, whether they are in a Mercedes-Benz or a BMW, run properly off the engine to lower the radiator coolant’s temperature.

Final Section

We hope you got your answer to the query “Why Does My Car Fan Keep Running After I Turn It Off?” So, the fan keeps running due to low coolant level, overheating, leakage, corrosion, defective PCM and ECU, cable failure, a faulty sensor, radiator issue, and more. Therefore, you need to keep checking these things to solve the issue.

However, if you need more information related to fan running but the engine not running issue, feel free to ask in the comment box. We would love to give you a proper response as soon as possible.

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