Why does the radiator fan come on when the car is not running?

On some modern vehicles, an ambient air temperature sensor, vehicle speed sensor, and other sensors may provide input to the car computer to determine radiator fan operation. Consult your vehicle repair manual to check the required sensors and switches. On a warm engine, the fan may come on even if the engine is not running.

When to troubleshoot an electric car cooling fan?

On a warm engine, the fan may come on even if the engine is not running. When working on a hot engine or an engine that is running, keep your hands and tools away from the fan blades and moving components. Troubleshooting a cooling fan that doesn’t work can be a relatively straightforward task at times.

What does it mean when your Sonic radiator is not working?

If the radiator fan is not working, it’s a serious problem. Just because the radiator fan is not on does not mean that it is not working. They are designed to only run when needed. If your Sonic is running hot, and the fan is not running we’ve laid out the most common causes of this issue below.

Why does my AC fan not come on?

When the ac is of the radiator hoses both become same heat after a while and the overflow reservoir starts boiling over and the fan do not kick in. Any advise please. You might have an initial temperature sensor which causes the fan to come on when the temperature begins to rise; that sensor might be defective.

Why does the radiator fan not come on when the AC is on?

In order for the AC Condensor to do its job it must stay as cool as it can. As for the engine coolant temp sensor, if the coolant is not hot enough to make the fan come on, then there is no need for the fan yet and there is no problem.

Why does my car fan come on when the engine is not running?

Consult your vehicle repair manual to check the required sensors and switches. On a warm engine, the fan may come on even if the engine is not running. When working on a hot engine or an engine that is running, keep your hands and tools away from the fan blades and moving components.

Can a bad fan relay cause an engine to overheat?

However, a bad cooling fan relay isn’t the only culprit for excessively high engine temperatures. Many other issues can cause the engine to run hot or overheat. Rather than uncommonly high engine temps, the driver may notice that the cooling fans have stopped running.

How does the cooling fan relay work on a car?

The cooling fan relay is the relay that controls the engine’s cooling fans. When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans. The relay will usually be activated once it is detected that the vehicle’s temperature…

What are the symptoms of a bad cooling fan relay?

1. Engine running hot One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. If you notice that your engine is running at higher temperatures than normal, that may be a sign that the relay is not functioning properly.

Why are my cooling fans running at all times?

3. Cooling fans stay on at all times. If the cooling fans are staying on at all times, this is another (less common) symptom of a possible problem with the cooling fan relay. If the relay shorts internally, it may cause power to be permanently switched on, which will cause the fans to run at all times.

Why is the radiator not working on my Toyota Corolla?

If everything else seems on the up and up, the springs in the fan clutch have worn past the point of proper function and can no longer do their job. There are many reasons why your Toyota Corolla’s radiator fan is not working. Of all the ones listed above, start with the coolant level, then check the fuse. After that, the order isn’t so important.

Why is my 2005 corolla fan constantly running?

Checked the pressure switch resistance on my 2005 Corolla. Verified that there was continuity between the pins for AC control (as designed) and no continuity between the fan control pins with the engine running. So at this point I was pretty confident I had a bad pressure switch as the culprit.

Is it bad if the fan motor is not running?

Keep in mind that just because the fan motor isn’t running, doesn’t mean it’s bad. If the power supply is fine and the windings are in good shape, check the capacitor next. The capacitor helps the fan motor run.

How to test the fan motor on your air conditioner?

To test the fan motor on your air conditioner, you’ll have to do a continuity test. It might be best to call a professional for this, but if you have the know how we have many AC unit motors in stock as well. Step 1.

Why are the cooling fans not working on my car?

1. Engine running hot 2. Cooling fans do not function 3. Cooling fans stay on at all times Average rating from 129,472 customers who received a Vehicle Engine Cooling Inspection. Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool.

How to troubleshoot an electric cooling fan problem?

1.Has the Cooling Fan Actually Failed? 1 If the fan comes on when the AC is running at MAX, but doesn’t run when the engine is hot, check the temperature sensor… 2 If the fan fails to come on, first check for a fan blown fuse or triggered breaker. On older vehicle models, you may… More

What are the symptoms of a bad radiator fan?

$0.00 1 Cooling fans do not come on The most common symptom of a faulty cooling fan motor are cooling fans that do not come on. 2 Vehicle overheating Another symptom of a possible problem with the cooling or radiator fan motors is the vehicle overheating. 3 Blown fuse

What are the symptoms of a bad cooling motor?

As they are the component that rotates the fan blades and creates the air flow, any issues that eventually arise with the fan motors can quickly develop into other problems. Usually a bad or failing cooling fan motor will display a few symptoms that can alert the driver of a potential problem that should be serviced.

What to do if your radiator fan is overheating?

Check the coolant level in your engine. The simplest way to do this is to look at the reservoir in the engine. It will be marked with maximum and minimum levels. Always make sure the coolant level is up near the maximum level to avoid possible overheating. 5. Fan Clutch

How many volts does a radiator fan need?

They should be putting out around 12 volts of direct current. Use a voltmeter to check that there is current present. If there is not, you need to check both the wires and the fan relay to see if replacement is required. The fan relay will be under the hood.

How does a Radfan fan work on a radiator?

The Radfan is super quick to install. Simply take it out of the box, plonk it on top of your radiator, plug it in and forget about it – the Radfan will turn on when your radiator gets warm and off again when it cools down. No plumber or electrician needed, it’s as easy to install as a desk lamp.

Why is my radiator fan not working at low speed?

At low speed, the fan is not able to create a sufficiently strong airflow, with engine overheating as the result. Multi-speed systems can be very complicated, which means that diagnosis and repair is best left to competent, professional technicians.

How does the fan work on a radiator?

In the vast majority of cooling system designs, the fan is controlled by a simple bi-metal switch that is in direct contact with the coolant. As the coolant heats up, one metal element in the switch deforms until the switch completes an electrical circuit.

If the cooling fans are staying on at all times, this is another (less common) symptom of a possible problem with the cooling fan relay. If the relay shorts internally, it may cause power to be permanently switched on, which will cause the fans to run at all times.

What are the symptoms of a bad cooling fan resistor?

Another symptom of a potential problem with the cooling fan resistor is cooling fans that stay on at all times. If the resistor shorts or fails, it can cause the cooling fans to stay on even when they are not supposed to.

Why is the cooling fan running all the time?

My name is XXXXX XXXXX Im happy to help you with this… This is usually a bad connection on the Ect ( engine temp sensor ) so check the wiring / plug connections – to that. Pull the connector off and check the connections – if they are ok, re fasten the connector on…and see if thats stopped it.

What happens when a radiator relay goes bad?

A faulty or broken relay cannot deliver power to the cooling fans. In turn, the unpowered fans won’t run, leaving the radiator to its own devices. Deprived of the helpful influx of air from the cooling fans, the radiator cannot remove as much heat as it usually does.

Why does the radiator cooling fan stay on high speed?

When I drive, the cooling fan comes on turbo mode and truck is not running hot. The fan stays on high and will not go off until truck is turned off. Heat inside the car is hot and truck does not overheat. Coolant level is perfect. helpful? So I assume this did not do this before you made this repair of the water pump?

When does the cooling fan come on or off?

I’ve read that the cooling fan will run the whole time when either the A/C is on or the vent control is set to defrost, regardless of whether the engine is cold or hot. In my case, the cooling fan comes on when the engine is cold, even with the HVAC off and it will remain running at full speed when the engine is running, again with the HVAC off.

Why does the radiator fan come on when the car is not running?