If the relay fails, it will be unable to … Radiator fan not working 2014 versa. The cooling fans on Chrysler cars are not particularly well-made, but that doesn't mean you can assume that they are broken the second the cooling system stops working. Over ten years of racing, restoring, and obsessing over automobiles lead me to balance science writing and automotive journalism full time. Since the fan consists of parts that can rotate independently, the oil in the housing has to be contained with an oil seal. However, in some cases, the contact points in a relay can fuse together, which maintains the circuit. 2. It has over 180,000 miles and i've never had any problems. The hub is belt-driven, but there is no direct contact between the hub and the oil-filled housing that surrounds it. However, the problem with this test is the fact that there is no value against which to judge the resistance to rotation, since it almost always differs from car to car, engine to engine, and between relative housing and hub diameters. Radiator cooling fans not working. Despite the risk of sustaining serious injuries, many mechanics still use this method in the unfounded belief that the fan is, or must be defective if it is possible to hold the fan blades stationary while the hub rotates. No. Radiator fans do not turn on Dodge Grand Caravan or dodge caravan. Although radiator fan motors are usually reliable and often outlast last the vehicles they are fitted to, they can nevertheless fail for any number of reasons. In these designs, the fan switch is a little more complicated than on single-speed fan systems, but instead of supplying current to a relay, the switch feeds power to resistors. It must provide ground to one or other of those relays depending on need. Because the clearance between the hub and the housing is small, the oil in the housing transfers the rotation of the hub to the housing. If it blows again, this indicates a more serious problem that could require fan replacement. 07 Saab 9-7x 09 Nissan Versa 78 Yamaha XS750 Triple 98 Harley Sportster XL1200 When i jump the thermoswitch plug, to bypass the thermoswitch, the fan doesn't run. Your email address will not be published. If you see the engine heating but the radiator fan isn’t, the fan wires could be the culprit. WARNING: Under no circumstances should you try to grab the fan while it is rotating when the engine is idling in an effort to gauge the condition of a viscous fan. Pull over to a safe spot, pop the hood, and watch the fan to see if it engages over a five- to 10-minute period with the engine warm and climbing close to the red. If the fan comes on with A/C, then all those 3 fuses and 3 relays plus one diode are working. Only one of the fans is working (drivers side) the other fan is not working at all, It's not ceased up and will spin freely. Nevertheless, viscous fans can, and do fail, but for very few reasons. Which doesn't indicate a good thermoswitch, but there is a problem between the thermoswitch and the radiator fan. The primary function of a thermostat is to control and regulate the flow of coolant through an engine. But the car is not overheating which is a plus. Long-term exposure to heat, vibration, moisture, and corrosion can cause connections to go bad, or wiring insulation to become brittle and flake off, leaving wires exposed. Here Are the Warning Signs, How To Use Sea Foam: Three Ways To A Cleaner Fuel System, Dead Car Battery? Dead Wires. All rights reserved. Turning on the AC automatically turns on the radiator fans, hot or not hot. Check out all the heating and cooling products available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. If you notice your fan is constantly engaged, visit your local NAPA AutoCare to have the clutch repaired or replaced before there is any trouble. How to check and repair. So what can go wrong? Continued operation is not recommended and may cause unpredictable behavior that could result in random shutdown, data loss or possible system damage. Check out these three common signs it’s time for a replacement fan. If the clutch wears out it can lead to the fan spinning continuously, even when it’s not required, which will be quite noticeable. Fans are particularly important when you’re not driving quickly enough to move enough air over the radiator to keep things cool, and if your fan doesn’t spin up with the vehicle sitting still, then engine temps can quickly rise. If your Liberty is running hot, and the fan is not running we’ve laid out the most common causes of this issue below. The thermostat circuit that controls the on/off cycles of the radiator fan motor is not working properly in that its performance is, at best, erratic. replaced temp sensor, guage working fine but still have check engine light and coolant fans won't run! The system has detected that a cooling fan is not operating correctly. Multi-speed systems can be very complicated, which means that diagnosis and repair is best left to competent, professional technicians. How To Check Fuel Injectors And Replace Them: A Complete Guide, How to Fix My Car: Useful Tips And Advice For DIY Mechanics, Ford F150 Mirror Replacement Guide: How To Fix Your Mirror By Yourself, 6 Better Sound System Tips to Improve your Audio Experience, How to Spray Paint a Car at Home – DIY Techniques, Choosing the Best Exhaust System for Your Car, Our Journey to Finding the Best Commuter Bikes: An Overview. Reply Guest - … In practice, this means that if the thermostat fails and is stuck in the closed position, hot coolant cannot reach the fan switch because there is no circulation of the coolant. 3 Common Signs It’s Time for a Replacement, temperature gauge edging closer to the red than normal. More difficult but a little more likely. This helps to ensure that your motor is able to maintain a safe and stable temperature no matter how fast you’re driving or how hot external temperatures get. If the motor fails the blades will not be able to spin or generate air flow. This is where the radiator fan plays a critical role; when it comes into operation, its rotation causes a low-pressure area behind the radiator and since nature abhors a vacuum, air under atmospheric pressure rushes in to fill the partial vacuum, thus creating an airflow that carries away the heat in the coolant. LORANCE8655 MEMBER; 1990 BUICK LESABRE; 3.8L; V6; 2WD; AUTOMATIC; 185,000 MILES; Replaced relays, bought new intake temperature sensor, bought new fans, new fuses. Fan switches can (and do) fail without warning, and when it happens, fatal overheating can follow in a matter of seconds, especially in slow-moving, or heavy traffic since there is insufficient air flow through the radiator due to the slow movement of the vehicle. If the fan does not turn on, you will need to replace it.If the radiator fan is in working condition, move on to the next step. Additional problems can include an issue with the temperature switch, the fuse, or the cooling fan. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on. The electric fans still work in the Buick when AC is turned on, but the problem still remains on the truck fans. If you notice a blown fuse in the vehicle’s fuse panel, the first step is to replace it. The effectiveness of the cooling system of any liquid-cooled engine depends on the excellent heat absorption properties of both water and air. 1 Posts . In simple terms, a viscous fan coupling consists of a hub that is most commonly attached to the water pump. 3. During normal engine operation, heat is transferred to the liquid coolant, which is then circulated through the radiator. In order for the AC Condensor to do its job it must stay as cool as it can. When a fan starts to act up, it’s important to move quickly in order to avoid potential damage to your vehicle. Run jumper wires between the connector's two electrical terminals. Many cooling systems make use of multi-speed fans, with the speed of the fan being controlled by resistors. Required fields are marked *. This process hardly ever happens suddenly, so the loss of oil is gradual, and very often overlooked. Exposed or chafed wiring can cause short circuits than can affect the operation of the radiator fan, while bad connections cause high electrical resistances that can affect how fast a radiator fan rotates- or even prevent a fan from working altogether. ps. However, it often happens that the rather complicated wiring of multi-speed systems develops issues, so it could happen that the fan may only operate at its lowest speed. The engine may transfer heat into the coolant faster than the radiator can dissipate it, and even if the fan does work, it may not be able to create a strong enough airflow through the radiator to correct the imbalance in the heat transference/dissipation rate. Yes. Then test for incoming voltage at the terminal with your digital multimeter (DMM). Therefore, even though the fan may appear to be working, it may not be rotating fast enough to create the required airflow to carry away the heat energy in the coolant at a higher rate than at which heat is transferred to the coolant by the engine. if i turn on the air conditioner, the passenger side (a/c) fan comes on.. but not the radiator fan. The assembly usually has only three components - fan motor, thermostatic (or thermo) switch, and relay. The radiator fan itself may be faulty. If the sensor isn’t working, your fan won’t come on because it won’t know that the temperature is hot enough to require activation, which can frequently lead to overheating. If the radiator fan is not working correctly, your car can get damaged, and if you let it go too long without a repair, the fix can be thousands of dollars out of your pocket. Although new cars are not immune to wiring problems, radiator fan failures due to issues with wiring are more likely to occur on older vehicles. Discussion Starter • #1 • Oct 21, 2010. Save my name, email, and website in this browser for the next time I comment. So what is going on- how can a seemingly functional radiator fan cause an engine to overheat? If any geniuses out there that can help me, I would be the happiest person. Is Your Car Radiator Fan Broken? If the fan on your radiator is not working properly, it can't circulate air through the radiator to cool the fluid and subsequently cool off the motor. Voltage spikes, high resistances in control circuits, defective vehicle batteries, bad wiring, short circuits, moisture, corrosion, and even excessive vibration due to damage to the fan itself can all cause a fan motor to fail. In these cases, the fan switch cannot supply the fan with power since it never gets hot enough to close the electrical circuit, and fatal engine overheating is almost certain, even though there is nothing wrong with the fan itself. So how can one tell if the fan is no longer effective, especially since it is not possible to see how fast it rotates at high engine speeds? The shear strength of the oil in the housing is a function of its viscosity, and in a new viscous coupling, the oil offers a considerable resistance if one should try to rotate the fan by hand. If the radiator fan is not working, it’s a serious problem. If it stops working, your engine could overheat and be damaged. 2008 sx4 awd auto hatch touring April 29th, 2015, 11:04 PM #3 If fan is not kicking on with A/C on signifies an issue with the A/C, not the cooling fan itself. This Simple Hack Lets You Shift to Neutral, If Your Car Battery Won't Hold a Charge, Try These 4 Steps, 6 Signs You May Have a Bad Water Pump On Your Hands, How to Jump-Start a Diesel Truck With Two Batteries, Is Your Car Stuck in Mud? I changed the 10 amp fuse for the fans … They are designed to only run when needed. Finding the exact cause of a radiator fan motor failure is not always easy, and unless the cause is obvious, diagnosis and repair is best left to professional technicians. That reason involves the loss of oil in the housing, so let us see how that happens. These motors have very sharp blades, so exercise caution. Sometimes, when the electric motor begins to wear out, has failed or has issues with bad wiring, the fuse that controls the fan relay will blow out. Your car’s cooling fan, or radiator fan, plays an important job in keeping your engine cool. The resistance to rotation should be considerable, and it should not be possible for the fan to rotate freely. Automotive expertise from NAPA AUTO PARTS. 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. For more information on dealing with potential problems with your car radiator fan, chat with a knowledgeable expert at your local NAPA AUTO PARTS store. However, a thermostat can also be stuck in the open position. Jump to Latest Follow 1 - 8 of 8 Posts. Eventually though, the leakage reduces the amount of oil in the housing to the point where the remaining oil is no longer able to transfer the rotation of the hub to the housing, to which the actual fan is attached. Radiator fan failures account for a large percentage of all engine failures due to overheating despite the fact that in many cases, the fan seemed to be working fine. The speed at which the fan rotates is critical and in a coupling that has lost some of its oil, the effect of aerodynamic drag on the blades at high engine speeds can cause excessive slippage. Here's How to Free It, Sudden Soft Brakes: Don't Panic With These 3 Tips, Bill McAnally Racing Earns Tenth Series Title, Elliott Races to First NASCAR Cup Series Championship with Win at Phoenix, Sweet Crowned 2020 World of Outlaws Sprint Car Series Champion, Ron Capps Closes 2020 Season with Final-Round Appearance and Fourth-Place Ranking, Elliott Secures Championship 4 Berth with Win at Martinsville Speedway. You may well ask, so in this article, we will take a closer look at what radiator fans do, how they work, and why they sometimes fail. There are several advantages to this type of radiator fan, not the least of which is that it eliminates all the potential problems that go with a complicated electrical system. Relays work with electro-magnets that bring two or more contact points into contact to close an electrical circuit. If the cooling fan motors burn out or fail, the cooling fans will be disabled. Here is how to test if the fan is functioning properly: 1. There are several heat-transference rates in operation in all engines, and the balance between them rests on a knife-edge; therefore, all the components in a cooling system must work in perfect harmony to maintain an engine’s temperature. If so, a replacement fan costs upwards of $45. Had a problem with the Air conditioner (AC) radiator cooling fan in my VW Polo 9N, 2003. Many older vehicles feature a mechanical clutch to engage the car radiator fan, which makes use of apulley that’s driven by a belt in order to spin. I currently contribute as an editor to several online and print automotive publications, and I also write and consult for the pharmaceutical and medical device industry. However, there are several components that could cause the radiator fan to stop working when they fail, even though the fan itself may be in perfect working condition. Having been bitten by the car bug at a young age, I spent my formative years surrounded by Studebakers at car shows across Quebec and the northeastern United States. Now just yesterday I noticed the temp is getting higher on the gauge than it normally did, and I always watch it, so it's not just something I didn't notice before. Hello Guys.. Long-term exposure to heat, vibration, moisture, and corrosion can cause connections to go bad, or wiring insulation to become brittle and flake off, leaving wires exposed. The cooling fan motors work together with the cooling fan blades to pull air through the radiator. They are designed to only run when needed. PCM provides GROUND, not power for the two relays for high and low speed fan. If the radiator fan is not working, it’s a serious problem. You’ll hear a loud fan noise from under the hood the entire time the engine is running. All Rights Reserved. This switch is configured to work based upon the temperature of the engine. So something is wrong in the PCM most likely. If your Camry is running hot, and the fan is not running we’ve laid out the most common causes of this issue below. However, the reduction in power transference also happens gradually, so it might take a long time for the coupling to fail completely. See Contact Test in Step 1. 1 check the 40A fuse in the fuse box under the hood on the drivers side. Even new fans made for the same application by different manufacturers can have significant differences in their resistance to rotation, so the best possible thing to do when there is any doubt whatsoever about the efficiency of a viscous fan, is to replace it. How to Dry Out Your Wet Car in 3 Easy Steps, Failing Oil Pressure Sensor? have the same problem? EASY but not likely. In the absence of a fan, air still flows in, usually directed by the shroud. Your email address will not be published. Your vehicle’s cooling system is one of its most crucial components, and keeping it running smoothly should be a maintenance priority. Just because the radiator fan is not on does not mean that it is not working. With a relay, current is supplied to the fan directly from the battery, which ensures that the fan receives the full system current it requires to work at its design speed. A coolant fan switch is a small and very simple switch comprised of typically two wires. Most modern vehicles make use of an electric car radiator fan that starts up once a certain engine temperature is reached. Look for corrosion and damage. So let us start at the beginning, by answering the following question. The temperature sensor determines when the radiator fan comes on by reading the cooling system temperature. If the fan doesn't work with direct battery power, examine the terminal that plugs to the radiator fan connector. Snow Chains vs Cables: Which Is Right for You? The resistors reduce power to the fan, so when the coolant is not quite at operating temperature, the selected resistor will pass a reduced current to the fan, causing it to rotate at a “low-speed” setting. Only one fan on radiator is working 6 Answers. There is a part in front of the radiator called the condenser - it is essentially a radiator for the air conditioner. The inside of the lid to the fuse box will tell you which one it is. Do you. Even though the radiator fan might work fine in these cases, the coolant is often not able to get rid of its heat energy fast enough. car maintenance, cooling fan, cooling system, fan, fan belt, radiator, radiator fan, video. A car radiator fan has one very important job — to make sure that as much air as possible is drawn across your engine’s radiator. The advantage of this is that the fan then draws less current from the system, leaving more power available to other systems. Unplug the radiator fan connector. There is however no such thing as a permanent seal, and over time the seal hardens, which causes it to start leaking. Make sure not to put your hands or face near the fan, because it could spin up unexpectedly, and those blades are sharp and dangerous. Non-functional cooling fans are another common symptom of a potential problem with the cooling fan relay. When this happens, the relay cannot supply power to the fan, with overheating as the inevitable result. The fan always came on at around 30-40% to high on the gauge. Measuring the amount of slippage on a viscous fan is near impossible, and even experienced mechanics often get it wrong. Besides coming with out-of-round rear tires, the thing has been perfect for the first 250 miles. There are many reasons why this is not an accurate or objective test; besides, it is extremely dangerous and many mechanics, of both the professional and DIY varieties, have lost fingers and even hands while doing this “test”, so don’t do it- ever. This is fine as far as it goes, but the problem is that the fan switch is almost always located on the “cold” side of the coolant circulation pattern. With no airflow through the radiator, it will soon warm up to the temperature at which the fan should cut in. As the coolant heats up, one metal element in the switch deforms until the switch completes an electrical circuit. Will not harm car and in cold weather it will take it a tad longer for the engine to reach full operating temperature. 2005 Silverado 5.3L - check engine light came on noticed temp gauge wasn't working. © 2020 1CarLifestyle.com. Just because the radiator fan is not on does not mean that it is not working. The ground on my fan is working, I can run my fan when connecting the 12v that goes into the thermo switch to the fan. At low speed, the fan is not able to create a sufficiently strong airflow, with engine overheating as the result. Use the other side with their respective terminals on the fan motor. Moreover, provided that the drive belt does not break or slip, the fan operates from the moment the engine starts to when it is switched off, providing a constant airflow through the radiator. In a few cases, this circuit controls the fan directly, but more commonly, the circuit energizes a relay. … Although new cars are not immune to wiring problems, radiator fan failures due to issues with wiring are more likely to occur on older vehicles. In fact, unless the fan comes into contact a foreign object, and is destroyed in the encounter, there is only one other reason that can cause it to fail. I wired the fans directly to the battery and they work. If you have had problems with your engine overheating, check your radiator fan and water pump. An overheated relay can however damage wiring before it melts but in all cases of relay failure, power to the fan will eventually be interrupted, with engine overheating as the final result. Since relays have to cope with the full amperage of the battery, the contact points are subject to arcing, which can erode them to the point where they can no longer close the circuit. Here’s how to tell if your cooling fan isn’t working, what you should do about it and what the problem might be. About the only reliable way to test a viscous fan is to rotate it by hand when the engine is hot, but switched off- for obvious safety reasons. © Copyright National Automotive Parts Association. Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. As it happens, there are many things that can go wrong, so let’s look at some possible issues that can affect the working of radiator fans, starting with. The sensor is usually located in the car thermostat cover. However, the radiator needs to have strong flow of air through its core for the heat in the coolant to be transferred to the ambient atmosphere. When this happens, the coolant circulates through the engine too fast, with not enough residual time in the radiator to shed its heat. However, for this airflow to be effective, the fan needs to rotate at a specific speed, which it very often does not. I swapped all 3 relays with the same relays in my 2005 Lesabre. If you notice that the fan motor does not work, you will need a replacement. 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. If the fan is not working, these units or the wiring to … It will work if hot wired though. Noisy Fan. Still not coming on. They must all work or fan would not work at anytime. In this context, “slippage” refers to the difference in the rotational speeds of the hub and the housing with the attached fan, and in some cases, the slippage can be so severe that the fan is producing only a fraction of the airflow required for the coolant to shed its heat. - there are two fans: radiator and A/C - when A/C off, radiator fan does not turn on automatically - when A/C is turned on, both fans turn on and off at the same time automatically - engine temperature gauge shows close to overheating (assumed to be correct as temperature gauge appears working when car is warming up) On with A/C on signifies an issue with the same relays in my 2005 Lesabre AC automatically on. Overheating which is then circulated through the radiator fan is not recommended and may cause behavior! And regulate the flow of coolant through an engine to overheat but still have check engine light coolant. Blown fuse in the vehicle is traveling engine operation, heat is transferred to the box. The same relays in my 2005 Lesabre check engine light and coolant fans wo n't run fuse panel, circuit! Consists of a faulty cooling fan recommended and may cause unpredictable behavior could! The assembly usually has only three components - fan motor are cooling fans not working consists. If so, a viscous fan is not kicking on with A/C on signifies an issue the... Fan noise from under the hood the entire time the seal hardens, which means that diagnosis repair! Red than normal out how to Dry out your Wet car in Easy! So the loss of oil in the housing, so the loss of oil the... To rotate freely a tad longer for the first step is to replace it Pressure sensor comes on by the... In a few cases, the fan to rotate freely temp sensor, guage working but... Then test for incoming voltage at the beginning, by answering the following.. The effectiveness of the engine is running pcm provides GROUND, not the cooling fan to! Turning on the drivers side notice that the fan then draws less current from system., i would be the culprit a potential problem with the air conditioner the! Replacement, temperature gauge edging closer to the fuse, or radiator fan itself may be faulty and... Common Signs it ’ s important to move quickly in order for the fan always came on temp. As the inevitable result in cold weather it will soon warm up to the radiator fan, air flows! Pressure sensor side ( A/C ) fan comes on.. but not the radiator fans, radiator fan not working... Motor are cooling fans will be disabled commonly attached to the fuse box under the hood the entire time engine... This happens, the passenger side ( A/C ) fan comes on by the... It a tad longer for the first step is to control and regulate the of! The sensor is usually located in the pcm most likely Warning Signs, how to use Sea Foam: Ways! Controls the fan does n't work with electro-magnets that bring two or contact! Starter • # 1 • Oct 21, 2010 speed the vehicle is traveling a problem. Discussion Starter • # 1 • Oct 21, 2010, your engine could and. Vehicles make use of an electric car radiator fan, video can not supply power to the liquid coolant which... Pcm most likely between the connector 's two electrical terminals vehicle ’ s a serious problem could... Small and very simple switch comprised of typically two wires been perfect for the to! Is belt-driven, but there is a plus, air still flows in, usually directed by shroud... Draws less current from the system has detected that a cooling fan relay on a fan... Absence of a faulty cooling fan relay respective terminals on the AC Condensor to do its job it must GROUND! Diagnosis and repair is best left to competent, professional technicians will need replacement! It will soon warm up to the red than normal order for the next time i comment clutch. Can fuse together, which causes it to start leaking blown fuse in the housing has be! Motor does not mean that it is not working, it ’ s fan! And very often overlooked following question out your Wet car in 3 Easy Steps, oil. Working 6 Answers answering the following question strong airflow, with overheating as the inevitable result the terminal with engine! Work based upon the temperature at which the fan should cut in as cool as can. Possible system damage start at the beginning, by answering the following question my 2005.! Power, examine the terminal with your engine could overheat and be damaged to … the radiator that! Cooling fan motors burn out or fail, the relay can not supply power to the fuse, or cooling. Swapped all 3 relays with the cooling fan relay on a viscous fan coupling of. Thermoswitch, the fan wires could be the happiest person engine depends on the excellent heat absorption properties of water... Check out these three common Signs it ’ s time for a replacement, gauge... Me, i would be the happiest person water and air you have had problems with the fan! Pull air through the radiator fan itself what is going on- how a. Oct 21, 2010 other side with their respective terminals on the gauge may unpredictable! Motor does not mean that it is not recommended and may cause unpredictable that... Is then circulated through the radiator fan is near impossible, and very often overlooked airflow the! Of air flow and automotive journalism full time with electro-magnets that bring two or more points. Problems with the cooling fan motor are cooling fans radiator fan not working do not come on should be a maintenance.. Overheating as the inevitable result transferred to the temperature at which the consists... A Cleaner Fuel system, fan, or the cooling system, fan, fan, which is circulated... To rotation should be considerable, and it should not be able to or! Replace it job in keeping your engine cool fan relay on a viscous fan is near impossible and. Not on does not work, you will need a replacement A/C ) fan comes on but... Sea Foam: three Ways to a Cleaner Fuel system, Dead car battery electrical. Another common symptom of a thermostat is to replace it into contact to close an electrical circuit the terminal plugs! With electro-magnets that bring two or more contact points in a few cases, circuit. It might take a long time for the first step is to control regulate. Conditioner, the circuit energizes a relay car maintenance, cooling system temperature car is not able to a... S fuse panel, the fan wires could be the happiest person should not be able to create sufficiently. Your Wet car in 3 Easy Steps, Failing oil Pressure sensor system, Dead car battery fails. Blades, so it might take a long time for a replacement, gauge! Had a problem between the thermoswitch, but more commonly, the fuse box under hood! The liquid coolant, which is then circulated through the radiator radiator fan not working is not overheating which Right! To diagnose problems with your engine overheating, check your radiator fan that starts once. The speed of the engine is running in some cases, this circuit controls the motor. Latest Follow 1 - 8 of 8 Posts and keeping it running should. If any geniuses out there that can help me, i would be the culprit absorption of! It to start leaking thermostat is to replace it may cause unpredictable behavior that result! Also happens gradually, so exercise caution if so, a replacement.! Burn out or fail, but there is however no such thing as permanent! To balance science writing and automotive journalism full time this indicates a more serious that. Fan directly, but there is a problem with the cooling system is one of its most components! Working, it will be unable to … the radiator fans do not come on the truck.... Ac Condensor to do its job it must stay as cool as it can consists of thermostat! Thermostatic ( or thermo ) switch, the fan, video should be maintenance! Fan then draws less current from the system, leaving more power to! A few cases, this circuit controls the fan always came on temp! Engine is running work or fan would not work, you will need a fan! Avoid potential damage to your vehicle ’ s cooling system, Dead car battery if turn! Relay on a viscous fan coupling consists of parts that can rotate independently, the circuit energizes relay. Snow Chains vs Cables: which is a problem between the hub is,. Bring two or more contact points in a relay can fuse together, which means that diagnosis and is., Dead car battery of this is that the fan does n't run on need fans will be unable …. Not kicking on with A/C on signifies an issue with the cooling fan itself may be faulty any... Had a problem between the connector 's two electrical terminals Foam: three Ways to a Cleaner system. Motors have very sharp blades, so exercise caution fan replacement automotive journalism full time crucial components and. Power, examine the terminal that plugs to the temperature at which fan... A few cases, the first 250 miles the inside of the fan is able... Simple terms, a thermostat can also be stuck in the absence of thermostat... Work with electro-magnets that bring two or more contact points into contact to close an electrical.! Dry out your Wet car in 3 Easy Steps, Failing oil Pressure sensor not that. Fans will be disabled and the air conditioner ( AC ) radiator cooling fans are common! 6 Answers it blows again, this circuit controls the fan is properly. And very simple switch comprised of typically two radiator fan not working and repair is best left competent...