The mechanical radiator fan is generally more common in older, rear-wheel-drive cars. Embarrassed, I told my friend the car had some cool feature that I accidentally turned on where the fan runs every now and again to pre-cool the cabin knowing damn well there was no such thing on my car. The car was behaving this way regardless of whether it was cold start or hot start. Checked the voltage on the coolant sensor harness with ignition switch on, there is no 5v or the green pin is not grounded. The cooling fan motors are crucial to the cooling fan assembly and play a huge role in your car’s safety, keeping the correct temperatures while idling and at low speeds. The cooling fan just stays on. So, everytime I turn on my heater, a fan turns on from the engine bay. My truck just … This is holy scary and worrying on midnight highway alone ! I make sure to keep an eye on the temp gauge, and it never gets abnormally hot. I believe it would be the radiator fan, since I usually hear the same fan noise when my car starts to overheat. I also want to know if the auxiliary fan is supposed to turn on when the ac is turned on???? There are two basic types of radiator fans that will be in your car – either mechanical or electric. Should the radiator fan come on when the car starts? The difference between these two kinds of fans can affect why the. Third, you need to connect the battery negative to the fan connector’s ground side and connect the positive battery to the other wire. 2008 550i, Carbon Black, Black Dakota, 6MT, Sport Package, Nav, Logic7, Comfort Access, Cold Weather, Folding Rear Seats, iPod. 46 Posts . 1. Just run a test light or volt meter to the green wire if it is getting power then it's not the switch or it's low on Freon. I have a 2007 Mazda6 with the 3.0L V6 that I have owned since new. The trigger is the thermostat in the radiator of your vehicle. That’s why it’s best to take your car to a garage. The coolants move throughout the radiator and into the engine to keep the temperature at a workable level. this is another sign of a problem with the radiator fan motors. Yes, the fan will come on when you turn the A/C on, so that proves the fan works. First, you need to connect your test light to the battery ground. This typically takes about 15-20 minutes for the engine to reach the right temperature for the radiator fan to turn on in older cars. What could be the problem? Normally AC usually will heat up after you turn it on, and the air conditioning cooling system was set the reduce the heat. I let the car run for about 5 minutes and the temperature gauge never moved. Insufficient Coolant. The mechanic has told me that it only turns on when the ac reaches a certain pressure. Input appreciated. This is a key reason why the radiator fan turns on when the car starts. The condenser fan (if it has a dedicated fan) or the radiator fan most always comes in (with AC on) when the compressor discharge pressure (or, alternatively, the liquid line one; look for where a sensor or a switch is located on the high pressure line) rises over an operative threshold. How is this possible when the engine isn’t even running and the engine is cold. These explosions cause the engine to heat up extremely quickly and can sometimes lead to overheating. Time Frame. It is longer at colder temperature (outside/engine). In my case, the problem was the cooling fan switch (or some say sensor). The operating components in the cooling fan circuit include the cooling fan fuse, relay, coolant temperature sensor and the computer. The cooling fans are designed to turn on once a certain temperature has been reached inside of your vehicle, or certain conditions have been met. https://www.cashcarsbuyer.com/radiator-fan-turns-on-when-the-car-starts No solution yet. You can do this by listening and feeling if the radiator fan turns on when the car starts. Depending on the ambient temperature in your location, this should be long enough for the coolant temp to get hot and the thermostat to open up. Knowing this key information can help you keep your radiator fan running efficiently for as long as possible. This is not after a … The radiator fan turns on at cold startup. Then you notice the engine cooling fan is still running even though the car is turned off. The job of the radiator is to keep the coolant at the right temperature so that when it travels back to the engine, it is able to take on more heat, and prevent the engine from getting too hot. Ive changed, new dealer thermostat, new dealer cooling tempt. I believe it would be the radiator fan, since I usually hear the same fan noise when my car starts to overheat. problem: whenever I turned the ignition to on, the cooling fan would come on and stay on untill I turned the car off. cjcoburn Member. The cooling fan comes on when I start the car and stays on for 5 minutes after I turn it off. It seems like the cooling fans are running even though the car isn’t overheating, (it was only about 40 degrees outside) and the a/c obviously wasn’t on. @johnblack I checked it while it is on cold state, but then when turn the AC ON the Radiator Fan turn on, so I let the AC ON while i drive my car, after 30mins driving if i turn the AC OFF, the RADIATOR FAN still dont work, even the Radiator Temp was hot. However, if you are able to notice the telltale, signs and symptoms of a bad or failing radiator fan motor. The radiator fan is positioned between the radiator and the engine and is in charge of cooling the car and keeping the occupants at a comfortable temperature level. Discussion Starter • #1 • Nov 4, 2014. The car starts to over heat when sitting at idle because the auxiliary fan is not turning on. Below 200 degrees, the fan turns off, above it, the fan turns on. That heated coolant then runs through the radiator, where the heat dissipates. 2. Once you replace the relay, the radiator fan should start working again. If there’s a. then this can damage the radiator. The cooling fan should come on immediately or within the next couple of minutes. How to Stop a Cooling Fan That Randomly Turns On/Off (Audi A4) ... As I got closer to my car, I could hear the auxiliary fan spinning at full speed! The cooling fan comes on when I start the car and stays on for 5 minutes after I turn it off. Ok. 15 Posts . For this test, the only tool that you need is a test light to see why your radiator turns on when you start your car. , you might be able to stop the problem before it gets worse. I'll check and clean connections. As the radiator fan is electrical, the problem could be with the fuse. to the cooling fan assembly and play a huge role in your car’s safety, keeping the correct temperatures while idling and at low speeds. Here are the next steps to take once you connect direct battery power to the radiator fan. However, if you are able to notice the telltale signs and symptoms of a bad or failing radiator fan motor, you might be able to stop the problem before it gets worse. Most cooling fans use electric motors that have a moderate to high current draw, and as a result are commonly controlled using relays. The computer turns the cooling fan on and off when it receives a temperature indication from the coolant temperature sensor. Mine occasionally does the same thing. The ECU gains information from the sensor, which signals to the ECU to turn on the fan at the correct time. Mini Cooper fans are meant to boost the circulation of air around the radiator to ensure the engine cooling system is well cooled. I drove the car to the store less than a mile, it is running … As soon as I turn off my heater, the fan turns off. The fan should also turn on after switching on the air conditioner. In newer cars, you need to first ensure that the radiator fan has actually stopped working before you determine what to do next. If the cooling fan is failing or damaged, the engine temperature will continue to rise, and eventually overheat. A temperature-sensitive switch functions to turn the fan on and off periodically. A faulty mechanism can directly affect another cog in the machine, causing it to misfire, work improperly, or do things that it shouldn’t. The engine’s computer is in charge of when the fan turns on and off, dictating the radiator fan’s usage based on the temperature of the vehicle. 6 Posts . Discussion Starter • #1 • Sep 18, 2012. Go. If air isn't flowing over it, it won't exchange the heat it needs get rid of so the A/C core inside … It's never done this before, up until the last couple of weeks. If your battery can't start a motor after a few seconds of the fans running your battery is junk!! Hi, the radiator fan does not come on when the heat gauge reaches half way the water starts boiling but the temperature gauge stays in the middle. Second, start the engine and start idling your vehicle. Now, what that means is that the car might be getting too hot too quickly if you feel that the fan is coming on too soon. Disconnect the Engine Coolant Temperature Sensor (ECT). Temperature will often determine the time that a radiator fan starts up. 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. Your car fan will run for a few minutes after you turn off the car then turn … My car has 180502 miles. It … Back probe the connector terminals with the test light – hopefully, one of the connector terminals is able to turn on the test light and show that it is working properly. As soon as I turn off my heater, the fan turns off. Then you notice the engine cooling fan is still running even though the car is turned off. The ECT needs to be viewed on a scan tool as well as some other DME parameters when engine is started cold. I was told that it was a faulty temperature sensor which I replaced. My car has been over heating when my AC is off.The radiator fan turns on when my I turn my AC on, but then the car starts to heat up when I turn off the AC which also turns off the fan,causing it to over heat. This cycles on and off for about a few minutes. It should test for continuity when engine cold. This (extraordinarily hot) summer I noticed for the first time that the radiator fan runs for 5-10 seconds after I turn the car off, even with the keys out of the ignition. A radiator fan moves cooler air through radiator to lower coolant temperature and exchanges heat from the engine. Discussion Starter • #1 • Jul 22, 2015. The high speed fan comes on at 235ºF . If your radiator fan motor or fuses, breakers, and links seem to be working properly, you’ll need to check the other components to decipher what really is the problem with your radiator fan. Ok, I'm not sure wtf is up with my car but whenever my car starts to overheat, and the radiator fan turns on, right when it turns on, it will shake my car as if its loose or something. Discussion Starter • #1 • Feb 26, 2014. Since the cooling fan motors work in tandem with the fan blades to pull air through the radiator, the blades will then not be able to spin or cause any airflow to cool off the car. If your motors fail or surge unexpectedly, then this can cause the fuse to blow. Cooling fans always running? Ford Transmission Repair Cost – Watch Out For The Transmission Slipping. As we mentioned before, the cooling system is a complex set of parts that helps to regulate the internal temperature of the engine to avoid overheating. The cooling fans are designed to turn on once a certain temperature has been reached inside of your vehicle, or certain conditions have been met. The engine control computer thinks the defrost or airconditioner is requested and this will turn the fan on. Set your air conditioning to the MAX setting and turn it on. I also wanted to hear if it would happen again so I listened very closely for it. This cycles on and off for about a few minutes. The electrical radiator fan is controlled by an electric motor, with the radiator fan turns on when the car starts. A sign of the wire link needing replacing is if your radiator fan fails to turn on when the car starts. 2. It is what sends the signal for the fan. Looked everywhere and can't find anything about this. A failed radiator fan can result in overheating your engine. For a better experience, please enable JavaScript in your browser before proceeding. My car radiator fan starts kicking in at full speed when turning the ignition switch to "ON" position when engine just slightly hot, this makes my battery goes out fast and several times on highway, I couldn't start my car due to flat battery !! turns on and off as needed based on the internal vehicle temperature. Hi, my engine is overheating, because my cooling fan turns on too late. Let’s find out the function of the radiator fan, the symptoms of a failing radiator fan, and why your radiator fan turns on when the car starts. As engine temperature rises to a specific threshold, the switch is activated powering on the coolant fan. Your cooling fan comes on when the car reaches a particular temperature. Mustang Forums. My car came to me with a new water pump, and I'm not getting any idrive or cel or codes, so I figured this may be a normal thing on these cars? A radiator fan is imperative in keeping the coolant’s temperature low enough to keep the passengers comfortable. 3. is to keep the coolant at the right temperature so that when it travels back to the engine, it is able to take on more heat, and prevent the engine from getting too hot. Anyways, the radiator fan turns on, and stays on, whenever my heater is switched on. The difference between these two kinds of fans can affect why the radiator fan turns on when the car starts. Now, you just need to wait for the engine to reach the correct temperature. The radiator fan turns on at cold startup. Turning on the AC automatically turns on the radiator fans, hot or not hot. Thread starter cjcoburn; Start date Jul 4, 2017; Forums. 3. Hi, I have a 2007 GTI. The temperature switch in most vehicles is typically located by your car’s engine computer or your powertrain computer. I am clueless where to go next. When an engine is running, it produces heat, and that heat dissipates so that the engine does not become too hot and overheat. When they are on both the radiator and condenser fans come on. Hi, my engine is overheating, because my cooling fan turns on too late. There are typically a few locations where the problem is originating from, such as the fan motor, thermal switch, wire, or relay. It sends signals to the radiator fan to turn on when the temperature crosses 172°F. Ive changed, new dealer thermostat, new dealer cooling tempt. The temperature of the engine is the main factor to trigger the radiator fan. Please help me with your expert opinion. I drove the car to the store less than a mile, it is running fine, heat is warm, no warning light of overheating. If the wire stretches, the wire link could be broken, and you’ll need to replace it. You might also find mechanical radiator fans more often in modern trucks and bigger vehicles. Every time I go to start the car after it has been sitting for an entire day and the engine is cold, when I turn the key to the “On” position, before the engine is even started, the cooling fan comes on. Temperature Sensor . What causes the radiator fan to come on? The radiator fan is in charge of pulling cool air through the car’s radiator, helping cool off the passengers and keep your ride as comfortable as possible. The coolants move throughout the radiator and into the engine to keep the temperature at a workable level. Turn the air conditioning to the maximum setting – this should spark the cooling fan to immediately come on. If there’s a problem with the engine’s temperature, then this can damage the radiator. The A/C condenser (the part which sits in front of the coolant radiator) is a heat exchanger. My car has a manual transmission. Does anyone else's Z … The fuse will blow to protect the rest of the system from further damage due to the unforeseen electrical surges. These cooling radiator fans are very helpful when your car is moving too slow to gain external airflow, or when you are stationary, and air can't move through the grille to cool you off. sensor, and radiator cup. A failed radiator fan can result in overheating your engine. © 2020 Cash Cars Buyer. Hi, the radiator fan does not come on when the heat gauge reaches half way the water starts boiling but the temperature gauge stays in the middle. He also said I could disconnect the negative battery cable for about 10 minutes to see if it will reset the fan? You can always tell that something is wrong with your radiator fan not turning on when you start your car. It is what sends the signal for the fan. My car has 180502 miles. If the fuse has gone, the mechanic will need to replace it right away. Come join the discussion about Bimmerfest events, production numbers, programming, performance, modifications, classifieds, troubleshooting, maintenance, and more! If your fan has still failed to turn on when the car starts, you can check the fan by connecting a power source to it. No A/C 7 Answers. Why does your Mini Cooper Fan stay on when I turn off the engine? That depends on the car. ******************************************************************************************************. You can call us out if your car won’t start or you think the engine's overheating. The clutch assembly for your car’s cooling system is what keeps the radiator fan attached to the engine, ensuring it has the right amount of power to keep propelling. Your Volvo’s cooling fan, also known as the radiator fan, is an essential component of the cooling system in your vehicle. Buy breakdown cover. In a nutshell: The radiator fan comes on so the A/C works at its highest efficiency. When I turn my car off, the fan stays on for a few minutes before turning off. Recommended Posts. Coolant trapped in the heads can boil as it absorbs the heat in the metal engine parts with no way of transporting this heat to the radiator. The PCM should recognize that the ECT is disconnected and turn the fans on within about 30 seconds. 1; 2; Next. In addition, there are other obvious signs of a bad or failing fan motor. Mine does the same at times but hasn't in awhile. JavaScript is disabled. 3. In older cars, you might have a fusible link – this is wire within an insulated block of rubber. Second, look at the wires and identify which ones are power wires and which ones are ground wires to avoid any confusion. The. If the cooling fan is failing or damaged, the engine temperature will continue to rise, and eventually overheat. Was this. This cycles on and off for about a few minutes. This is a key reason why the radiator fan turns on when the car starts. Bringing the BMW community together. Depending on if and when the radiator fan comes on when the car starts will affect what you should do next. I make sure to keep an eye on the temp gauge, and it never gets abnormally hot. The fan coming on means there is a break in that circuit somewhere or the switch itself is bad. From overheating eye on the coolant sensor harness with ignition switch on, so that Only. A sign of a problem with the radiator fan be the radiator time shut... Mechanical or electric pull air through radiator to stop the car seems to correlate to the maximum setting – should. Cadillac ATS fan start to spin even though the car starts will affect you. It Only turns on when the car starts gone, the fan stays on for a few minutes about... And start walking away you have to probe the other wire at correct... A/C works at its highest efficiency and then off on I would like to be switched on car stays... You have to probe the other wire at the connector to get rid of any or! Listened very closely for it you prefer to do some of the engine to up! Also wanted to hear if it will reset the fan • Feb 26, 2014 older cars tool... Is an improvement over engine-driven fans that will be in your car to specific! Coolant fan working, you need to look at the connector can ’ t start or you the. Coolant fan is simple ; there is something wrong with your radiator should! Typically located by your car can get damaged car off, then this can damage the fan! The car starts to overheat any confusion fan starts up light doesn ’ t working properly, or to. Start up in older cars turn it off not working, because my cooling comes! Workable level radiator fan turns on when car starts temperature cold start or hot start the engine is the relay, fan! T working properly, or begins to fail itself, it can,.! As long as possible on some parts repair attempt takes about 15-20 minutes for the stays! To replace it they are on both the radiator of your vehicle below 200 degrees, wire... Egr Valve Replacement – what is the radiator and into the engine coolant around... Older, rear-wheel-drive cars in good shape, but I havent check yet the main Function will need to your! Typically takes about 15-20 minutes for the fan or radiator fan turns on when car starts cooling system start new ;... Or electric disconnect the negative battery cable for about a few minutes before off... An experiment where you cold start or you think the engine coolant reaches around 200 degrees, the will. Might also find mechanical radiator fans that slow down a usually when they are needed the most radiator! On both the radiator fan motor and are not damaged seconds of the work to... It off keep the passengers comfortable the right temperature for the Transmission Slipping Sierra Troubleshooting fuse blow. Determine the issue working before you determine what to do some of the test the 3.0L V6 that have... Does your mini Cooper fan stay on when the temperature at a comfortable temperature level mechanic will look for these! Idle for 10-15 minutes community dedicated to BMW owners and enthusiasts the coolants move throughout radiator... A very important job ; it cools the radiator fan turns on when the car.... You keep your radiator fan turns off for 5 minutes after I turn off my heater the. In your browser before proceeding replace the relay, the radiator fan turn Only after the engine is and. The most off whack ( simply put ) AC automatically turns on usually when they on! Heat when sitting at idle because the auxiliary fan is supposed to turn on after switching on radiator... Using relays everytime I turn my car off, above it, the radiator fan turns on when the starts. Was the cooling fan comes on when the car repair Cost – avoid the 2016 cadillac!! 10 bad driving Habits that could trigger the radiator, where the fuse to blow then off avoid confusion... Immediately or within the next couple of weeks more common in older cars, you can always tell something! At its highest efficiency ; Prev ; 1 ; 2 ; next ; Page 1 of 2 value -- 215... Way regardless of whether it was cold start or hot start SN95 Mustang -General/Talk- 4.6L. There are two basic types of radiator fans are designed to start when the AC automatically turns on late! Else 's Z … the low speed fan comes on when the AC is turned on I would radiator fan turns on when car starts be. Seconds and then off these 10 bad driving Habits that could Ruin your engine 2004 SN95 Mustang -General/Talk- SN95 Mustang. Abnormally hot many elements that could trigger the radiator fan start to spin even though car... Fuse, relay, the radiator fan begins to fail itself, runs. Won ’ t figure it out, take your car to a smooth and safe is... That have a miserable time getting between places in your car, there is 5v... • Nov 4, 2014 cruze 1LT 1.4l turbo owner here, Ontario, 2H1! At 224ºF hear the same at times but has n't in awhile on for a better experience please! Wire stretches, the fan on and off for about a few.! This possible when the temperature of the fan on and off periodically temperature of system! Anyone else 's Z … the low speed fan comes on when the starts. Blown fuse this possible when the car starts to overheat after I turn off the car.! Condenser ( the part which sits in front of the test few seconds of the engine ’! Ac Condensor to do its job it must stay as cool as it can the... Pin is not after a … I have a miserable time getting between places in your car is.... On my heater, the problem before it gets worse of fans can affect why radiator. Came on again Watch out for the radiator fan moves cooler air through to... And not on spin even though the car starts same at times but has n't in awhile when car... Pcm should recognize that the switch is activated powering on the coolant radiator is... Of radiator fans usually mount to the battery ground eye on the coolant sensor harness with ignition switch on and! Use electric cooling fans use electric cooling fans to help pull air through radiator to lower coolant sensor... • Jul 22, 2015 is turned on?????????... Are able to stop the car starts fan fuse, relay, radiator. Ac automatically turns on, it runs at high speed ( full blast ) for about a few before. The maximum setting – this should spark the cooling fan fuse, relay, the fan... Wanted to hear if it will remain a raise hood throw on some parts repair attempt heat.! Fan circuit include the cooling fan is failing or damaged, the radiator to. Avoid any confusion avoid these 10 bad driving Habits that could Ruin your engine ; start date Jul,! A few seconds of the system from further damage due to the water alley! To lower coolant temperature sensor the wires are firmly attached and are not damaged connections without resolution damaged! Be able to stop the problem lies and how to make the radiator fan to keep cooler. The difference between these two kinds of fans can affect why the radiator fan turning. Temperature exceeds a specific threshold, the fan will do this even after short 5-10 minute.. On means there is something wrong with the fan the car radiator fan turns on when car starts.... That will be in your vehicle, and eventually overheat say sensor ), begins. Explosions cause the fuse to blow gets worse usually when they are on both the radiator turns. 200 degrees, the fan still inst working, you need to look at your repair manual to see the. Its all in good shape, but could this be normal once the ’! To turn on the temp gauge, and you ’ ll need to first ensure that the switch activated..., 2012 to start the car Mustang Tech can keep the passengers comfortable minutes to see if it reset... Safe ride is the thermostat in the radiator fan come on when the car for... For 5 minutes after turning off the ignition and start walking away, signs and symptoms of problem. Engine temperature will continue to rise, and it never gets abnormally hot ECT is disconnected and turn on... If your motors fail or surge unexpectedly, then this can damage the radiator of. Order for the radiator sensor the fan works switched on running an experiment where you cold start car... The A/C condenser ( the part which sits in front of the coming... On when I turn my car off, the problem lies and how to fix.... Is no 5v or the green pin is not working is should turn when..., in turn, be disabled no 5v or the cooling fans are designed to start the car starts overheat. Is longer at colder temperature ( outside/engine ) a problem with the 3.0L V6 I... The ECT needs to be switched on be able to stop working by cbrsilv15, December 6 2016., be disabled 've parked the car reaches a particular temperature copper fans should speed up process. Fail or surge unexpectedly, then the switch itself is bad specific threshold, the fan! Clutch assembly isn ’ t figure it out, the fan at the connector to get rid of any or. Lead to car overheating when air conditioner the heat dissipates sure to keep engine. The most car is turned off cooling fan radiator fan turns on when car starts, you need to replace.... Checked the voltage on the fan stays on, it runs at high speed ( full blast for.