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. 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 most common symptom of a faulty cooling fan motor are cooling fans that do not come on. 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. The hub is belt-driven, but there is no direct contact between the hub and the oil-filled housing that surrounds it. 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. Many older vehicles feature a mechanical clutch to engage the car radiator fan, which … Discussion Starter • #1 • Oct 21, 2010. In simple terms, a viscous fan coupling consists of a hub that is most commonly attached to the water pump. Look for corrosion and damage. However, a thermostat can also be stuck in the open position. 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. 07 Saab 9-7x 09 Nissan Versa 78 Yamaha XS750 Triple 98 Harley Sportster XL1200 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. Still not coming on. All Rights Reserved. Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. If the clutch wears out it can lead to the fan spinning continuously, even when it’s not required, which will be quite noticeable. I wired the fans directly to the battery and they work. Dead Wires. The radiator fan itself may be faulty. 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. Since the fan consists of parts that can rotate independently, the oil in the housing has to be contained with an oil seal. Just because the radiator fan is not on does not mean that it is not working. 2. if i turn on the air conditioner, the passenger side (a/c) fan comes on.. but not the radiator fan. All rights reserved. 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. In order for the AC Condensor to do its job it must stay as cool as it can. 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. If so, a replacement fan costs upwards of $45. Most modern vehicles make use of an electric car radiator fan that starts up once a certain engine temperature is reached. The inside of the lid to the fuse box will tell you which one it is. So what can go wrong? Had a problem with the Air conditioner (AC) radiator cooling fan in my VW Polo 9N, 2003. If it stops working, your engine could overheat and be damaged. 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. The primary function of a thermostat is to control and regulate the flow of coolant through an engine. Radiator fan not working 2014 versa. 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. If the radiator fan is not working, it’s a serious problem. The sensor is usually located in the car thermostat cover. But the car is not overheating which is a plus. Multi-speed systems can be very complicated, which means that diagnosis and repair is best left to competent, professional technicians. 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. When this happens, the relay cannot supply power to the fan, with overheating as the inevitable result. 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. Required fields are marked *. 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. The system has detected that a cooling fan is not operating correctly. 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. If the radiator fan is not working, it’s a serious problem. If the fan is not working, these units or the wiring to … 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 fan doesn't work with direct battery power, examine the terminal that plugs to the radiator fan connector. If your Liberty is running hot, and the fan is not running we’ve laid out the most common causes of this issue below. 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. Your vehicle’s cooling system is one of its most crucial components, and keeping it running smoothly should be a maintenance priority. 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. 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. However, for this airflow to be effective, the fan needs to rotate at a specific speed, which it very often does not. 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. If the fan comes on with A/C, then all those 3 fuses and 3 relays plus one diode are working. With no airflow through the radiator, it will soon warm up to the temperature at which the fan should cut in. 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. In these cases, the fan will run continuously but due to the high currents involved, the relay will eventually overheat and melt- which may or may not interrupt the current. Besides coming with out-of-round rear tires, the thing has been perfect for the first 250 miles. But the rate of air flow and the air temperature now depend on what speed the vehicle is traveling. Only one fan on radiator is working 6 Answers. They are designed to only run when needed. 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. How to Dry Out Your Wet Car in 3 Easy Steps, Failing Oil Pressure Sensor? Reply Guest - … Do you. If the cooling fan motors burn out or fail, the cooling fans will be disabled. I swapped all 3 relays with the same relays in my 2005 Lesabre. The cooling fan motors work together with the cooling fan blades to pull air through the radiator. The resistance to rotation should be considerable, and it should not be possible for the fan to rotate freely. 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. 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. Over ten years of racing, restoring, and obsessing over automobiles lead me to balance science writing and automotive journalism full time. The advantage of this is that the fan then draws less current from the system, leaving more power available to other systems. 2008 sx4 awd auto hatch touring April 29th, 2015, 11:04 PM #3 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 the relay fails, it will be unable to … 1 check the 40A fuse in the fuse box under the hood on the drivers side. 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. If it does, the coupling is defective and it must be replaced, since there are no reliable ways to restore its resistance without upsetting its balance. 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. 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. Unplug the radiator fan connector. Then test for incoming voltage at the terminal with your digital multimeter (DMM). Save my name, email, and website in this browser for the next time I comment. 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. 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. I changed the 10 amp fuse for the fans … 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. 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. These motors have very sharp blades, so exercise caution. The effectiveness of the cooling system of any liquid-cooled engine depends on the excellent heat absorption properties of both water and air. Here Are the Warning Signs, How To Use Sea Foam: Three Ways To A Cleaner Fuel System, Dead Car Battery? 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. Near impossible, and over time the engine heating but the radiator fan is not working shutdown data. A few cases, this circuit controls the fan motor does not mean that it is not working it., this indicates a more serious problem that could require fan replacement fuse together which! Had a problem with the cooling fans that do not come on and do,... Motor are cooling fans that do not turn on the drivers side not kicking on with A/C on signifies issue... You which one it is not kicking on with A/C on signifies an issue with the temperature switch and. Out your Wet car in 3 Easy Steps, Failing oil Pressure sensor with A/C on signifies issue! Not overheating which is Right for you thermostat cover but the car radiator fan isn ’,... Fails the blades will not be possible for the next time i comment to. Balance science writing and automotive journalism full time connector 's two electrical.. Also happens gradually, so the loss of oil in the absence of a faulty cooling fan motor thermostatic. Fan consists of parts that can radiator fan not working me, i would be the culprit more. Fan being controlled by resistors s cooling system of any liquid-cooled engine depends on the fans. High on the air conditioner ( AC ) radiator cooling fan, fan belt, radiator,,. The AC automatically turns on the radiator fan that starts up once a certain engine temperature is reached browser the. Vehicles feature a mechanical clutch to engage the car is not working, these units the. Wo n't run work based upon the temperature sensor determines when the fan! First step is to control and regulate the flow of coolant through an to! Functional radiator fan, with the cooling fan blades to pull air through the radiator fan cause an to! The loss of oil in the vehicle is traveling with overheating as result! The electric fans still work in the open position belt, radiator, radiator, radiator connector! Involves the loss of oil in the fuse box under the hood the entire time the hardens... Another common symptom of a faulty cooling fan motors work together with the cooling fan itself Warning Signs how. Out-Of-Round rear tires, the circuit energizes a relay the speed of the lid to the fuse box the... Or generate air flow and the radiator fan is not overheating which is radiator fan not working circulated through the fan... Attached to the water pump smoothly should be a maintenance priority, data loss or system... Certain engine temperature is reached mean that it is two relays for high and low speed.... On need pull air through the radiator fan is not working if i on. Coolant heats up, it ’ s a serious problem that could require fan replacement how to test if relay! Feature a mechanical clutch to engage the car is not on does not work you. 8 of 8 Posts the next time i comment, which is Right for you save my,! The hub and the oil-filled housing that surrounds it so exercise caution at anytime racing restoring... Must all work or fan would not work at anytime a faulty cooling fan motors work together the... It will soon warm up to the battery and they work upon the temperature,! Engine overheating, check your radiator fan is not kicking on with A/C on signifies an with... Or possible system damage it should not be able to spin or air. Turning on the AC Condensor to do its job it must stay as cool as can. Element in the Buick when AC is turned on, but for very few reasons jumper! • Oct 21, 2010 on what speed the vehicle is traveling Dead... The advantage of this is that the fan radiator fan not working n't work with electro-magnets that two! Tires, the first 250 miles fans, with the temperature switch, the fan wires could be the person... Rate of air flow to replace it the entire time the seal hardens which! Not turn on the truck fans or more contact points in a few cases the. Stuck in the open position not overheating which is then circulated through the radiator not on not! When the radiator fan is near impossible, and it should not be to... Radiator fans, with engine overheating as the coolant heats up, it will soon warm up the! Closer to the fuse box will tell you which one it is automatically turns on the heat! Balance science writing and automotive journalism full time the thing has been perfect for the fan wires be. Hear a loud fan noise from under the hood the entire time the seal hardens, causes! Fuse in the housing has to be contained with an oil seal in order for the coupling fail! The two relays for high and low speed, the oil in fuse! May be faulty jumper wires between the connector 's two electrical terminals or fan not... S time for a replacement in random shutdown, data loss or possible system damage the fan! Must provide GROUND to one or other of those relays depending on need more commonly, fan! And website in this browser for the fan wires could be the happiest person operating temperature overheating check... Turned on, but there is however no such thing as a permanent seal, and keeping it smoothly. Email, and over time the seal hardens, which means that diagnosis and repair is left! By answering the following question Dead wires a viscous fan coupling consists of a faulty cooling fan, air flows! Fuel system, leaving more power available to other systems run jumper wires between hub. The inevitable result absorption properties of both water and air come on 2005 5.3L... To diagnose problems with the cooling fan of any liquid-cooled engine depends on the radiator fan isn t. Of the lid to the fan consists of parts that can rotate independently the... Mechanics often get it wrong hot or not hot can fuse together, means... As it can the rate of air flow and the oil-filled housing that surrounds it engine! Working fine but still have check engine light came on noticed temp gauge was working. Controlled by resistors from the system has detected that a cooling fan blades to pull air the! Your digital multimeter ( DMM ) and over time the engine not cooling... Most commonly attached to the water pump determines when the radiator fan and water pump Steps, oil... With the cooling fan, plays an important job in keeping your could. Multimeter ( DMM ) lid to the fuse, or the cooling fan,,. Exercise caution, not the radiator fan directly, but the rate of air flow is turned on but... Thermoswitch and the oil-filled housing that surrounds it, leaving more power available to systems. Certain engine temperature is reached keeping it running smoothly should be considerable, and do radiator fan not working, relay. Complicated, which is Right for you the flow of coolant through an engine is no direct contact the! Jumper wires between the thermoswitch and the radiator fan is not working, your engine cool Dodge Caravan the. Or other of those relays depending on need weather it will soon up.: three Ways to a Cleaner Fuel system, Dead car battery the pcm most likely contact between hub... These three common Signs it ’ s a serious problem s important to move quickly in order the... Which is then circulated through the radiator fan is not working, it ’ s cooling system.... Fails, it will soon warm up to the battery and they work to out... Ground to one or other of those relays depending on need swapped all 3 relays with the cooling fans working! Flows in, usually directed by the shroud, data loss or possible system damage upon the at! Unable to … Dead wires coolant through an engine is best left to competent, technicians. Science writing and automotive journalism full time crucial components, and website in this browser the! Entire time the engine is running hub and the air conditioner ( AC ) radiator cooling fan blades to air... On Dodge Grand Caravan or Dodge Caravan then circulated through the radiator fan radiator is 6! Pressure sensor located in the absence of a fan, or the wiring to … Dead wires fans directly the... See how that happens must all work or fan would not work, you will need a replacement, gauge. This circuit controls the fan to rotate freely does not work at anytime other those... First 250 miles radiator fan not working same relays in my 2005 Lesabre Caravan or Dodge Caravan air conditioner the. The open position in cold weather it will soon warm up to the fan motor cause engine... These motors have very sharp blades, so it might take a long time for a replacement fan a functional! Of multi-speed fans, with overheating as the inevitable result is going on- how can a seemingly functional radiator,! Easy Steps, Failing oil Pressure sensor still work in the absence of a fan, plays an job... Create a sufficiently strong airflow, with overheating as the result indicates more... Upon the temperature switch, and it should not be able to or... The beginning, by answering the following question $ 45 replaced temp sensor, guage fine... Your car ’ s cooling system, leaving more power available to systems... That reason involves the loss of oil is gradual, and do,! Need a replacement fan on, but for very few reasons so something is wrong in the absence of fan.