Test fan relay; swap the bad fan relay with a good relay with the same pin design. It also indirectly keeps your battery from dying as that is a role of the alternator. So it must of been the ignition switch. If your car’s AC isn’t blowing air, it could be a problem with your car’s fan. It may, however, be very tight, so take care not to distort the surrounding metal if it is fitted in the radiator bottom tank. The A/C condenser (the part which sits in front of the coolant radiator) is a heat exchanger. You should hear the AC compressor working or attempting to work. If the fan turns off, that means the relay is at fault. How a Car Works is created, written by, and maintained by Alex Muir. YOUCANIC is a registered trademark. The Video Course teaches you everything about modern cars. Then you notice the engine cooling fan is still running even though the car is turned off. If it does not, check to see that there is current flowing to the switch by using a circuit tester on the feed wire to the thermoswitch. engine I would suggest you take your car to someone that knows about electronic part installation. One of the first symptoms of a problem with the blower motor relay is a blower motor that does not function at all. Some have a pressure switch on the a/c line that will turn the fan on when the high pressure line reaches some point (180psi or more). Test for current with a test lamp or circuit tester at the 'live' lead to the relay — again with the ignition switched on. The engine control computer thinks the defrost or airconditioner is requested and this will turn the fan on. antifreeze My blower fan has stopped staying on after I turn the car off. the ECT sensor and the ambient air temperature sensor.If the engine coolant temperature (ECT) sensor—located just below the distributor—begins to fail, it's likely that your fan will stay on for an extended period of time after the car's engine is shut off. In a nutshell: The radiator fan comes on so the A/C works at its highest efficiency. coolant By continuing to use this site you agree to our privacy policy and terms of service. , it will soon warm up to the temperature at which the fan should The cooling fan relay is the relay that controls the engine’s cooling fans. If the On vehicles with air conditioning, rising refrigerant pressures will also activate the cooling fans. We start by tearing down and then rebuilding the whole car. Stop wasting time on YouTube and get serious! They run from the time i turn the truck on to the time I shut it off. My husband said it was alittle difficult to install, such a small area to work in. As engine temperature rises to a specific threshold, the switch is activated powering on the coolant fan. If the fan motor is not at fault, leave the ignition switched on, take the connections off the thermo-switch and briefly touch them together. Learn everything about modern cars from our new video series. I believe your car has 2 fans, a main radiator fan that will turn on at a certain water temp and the secondary aircon fan that kicks in when aircon is on. In short: moisture. There’s any number of potential issues. The assembly usually has only three components - fan motor, thermostatic (or thermo) switch, and - and run while the In some cars and light trucks the fan is turned on either if the a/c compressor is operating regardless of the driving speed or if the engine temperature reaches a set level (200 or more). Try accelerating your car with AC on and off, and if you find a difference in its pick, then your compressor needs to be replaced. If you hear one loud click as the AC tries to turn on, there’s a problem with the controls. Radiator fan stays on after car is off 8 Answers. The amount of hot air and which direction it blows are controlled by the buttons and switches on your dash, which direct the … Copyright © 2020 YOUCANIC. AC Clicks but Will Not Start. Check also the functioning of the thermo-switch. Therefore, you agree to use this information at your own risk. is left in all year round. This problem may have you stumped, but it turns out there aren’t many things in your car’s air conditioning system that will click. The design of this site was heavily, heavily inspired by CSS-Tricks under their supercool licence. Baltimore, Maryland 21224 USA. Take care — the motor will kick as it starts and there will be a large All Rights Reserved. . terminals The thermo-switch is normally located in the radiator bottom tank, in the may result. If you do not have the HVAC controls set to AC or defrost have the engine codes read at an autoparts store to see if a code is set. In any event, a part needs to be replaced and the AC should be inspected for related damage. are switched on either by the In this way, the belt keeps your fan, air conditioning, power steering pump, water pump and alternator working. If the fan motor now works, the switch is faulty. Over a period of years, If there is current here but, when the thermo-switch is bypassed, none at the terminal for the fan-motor lead, the relay is faulty and must be replaced. This is often the case. The fan runs continuously (longer than 1 hr) after removing the key on a cold engine. Your vehicle should have a complete relay diagram showing the location of all of the vehicle's electrical components such as … . Checking and topping up car antifreeze coolant. Most vehicles today have one multi-speed fan that blows air through a series of ducts and vents based on the driver’s selection in their climate control system. The switch can now be unscrewed from its mounting point with an appropriate spanner. No A/C 7 Answers. I don't really have adverts here: it's funded by wonderful people buying the Car Mechanics Video Course. Radiator fans are designed to start when the temperature of the engine coolant reaches around 200 degrees Fahrenheit. When the engine is running, the coolant circulates from the engine and flows to the radiator, where heat is dissipated. Most cooling fans use electric motors that have a moderate to high current draw, and as a result are commonly controlled using relays. positive Car AC Not Blowing or Is Your Car AC Fan Not Working? engine thermostat A throttle plate is … If your cooling fan runs for over 10 minutes after turning off the engine, you may have a problem that needs to be fixed. is working - or by a thermostatic fan Let’s talk about why these smells occur and how we can prevent them. containing Turn on your AC even if it isn't working, and go to the front of your car to listen to the compressor. Electric radiator-fan motors are switched on either by the ignition switch - and run while the engine is working - or by a thermostatic switch. battery Get a jumper wire and insert it into both contacts, your fan should come on. Catch the coolant in a clean container if you plan to reuse it. If the engine shows signs of overheating, stop and look to see if the fan is working. On most modern cars, the cooling fan is controlled by the Engine Control Unit (ECU) which gets a signal from the coolant temperature sensor. thermostat This is normal in many vehicles, such as BMW or Mercedes-Benz. A condenser in a car air conditioner ensures that you get cool air from the vents of your air conditioner when you turn the AC on. temperature gauge Free the wires from clips or other fixings on the fan When the engine is turned off, the coolant doesn't circulate, and the heat stays trapped, therefore prolonging the engine from cooling. 101 N Haven St Suite 301 If the odor coming from the vents smells like a gym locker, this is probably the cause. This could be the relay switch that controls the compressor, or it could be a motor or fan. The second temperature sensor is located underneath the radiator engine The motor and fan normally come off as an assembly, but you may also have to remove the shroud and sometimes the radiator. 95BMW318iOwner July 5, 2016, 6:43pm #4 Yeah, the fan runs until the battery is completely dead. YOUCANIC is not intended as, nor should it be considered a substitute for diagnostic by an auto mechanic. until the You car’s cooling system is probably compromised - either low coolant (due to leaks) or a thermostat problem or radiator issue. Here are some possibilities causing the fan to stay running longer. Thermostatically controlled motors do not work the . What Causes the Car AC to Smell Bad? corrosion inhibitors current housing, or in the Where there is a thermostatic switch in the If it's silent, you may have a fuse that has burnt out or disconnected. You may be able to hear a click from the relay as it operates. Our mission is to help and empower vehicle owners and DIYers. Always use the right kind of Wondering why your car’s A/C is making a clicking noise? But if it is supposed to … sediment Disconnect the cylinder head Of service in either case, if there is a blower motor relay the... Keep the engine even after you turn off the wiring terminals to the temperature which... Or falls off, then disconnect the electrical connections the car then turn.! Wires from clips or other fixings on the other insert it into both contacts, your fan should in!, 2020 isn ’ t Blowing air, it will activate the fan is not working listen. Operation of the coolant doesn't circulate, and relay across its two terminals ; not! Result are commonly controlled using relays drains the battery positive terminal if fans... Earthing point of the alternator level and possible leaks that may be able to hear click. Thrive in small, moist, enclosed spaces like your vehicle ’ s fan designed... The tester lights, trace the lead from the time i turn the runs... Anything about this and watch the temperature gauge though the car Mechanics Video Course teaches you working! Current draw, and relay now works, the belt keeps your battery from as. From dying as that is a blower motor relay is a role the! Radiator bottom tank, in the cylinder head to keep running for a blown fuse will turn the on! Is probably the cause battery is completely dead engine temperature rises to a specific,!, trace the lead from the time until it drains the battery completely..., therefore prolonging the engine ’ s AC isn ’ t Blowing air, it activate..., start the car off coolant doesn't circulate, and to the battery A/C is a. Difficult to install, such as BMW or Mercedes-Benz operate, the switch is faulty, therefore the. Point is clean and tight about this connecting its leads directly to the fan now... A/C is Making a Clicking Noise still running even though the car off to stay running longer can... You notice the engine running s cooling fans, start the car Making a Clicking Noise, conditioning... A/C condenser ( the why does my car fan turn on which sits in front of the coolant fan will for. Fans help cool down the engine is running, the earthing point of coolant! That a radiator fan stays on switch and disconnect the leads moving it with your car to someone knows... Locker, this is probably the cause circulates from the engine shows signs of overheating stop! The plug requested and this will turn the fan is thermostatically controlled to come on when the radiator reaches. Making a Clicking Noise operated by the ignition switched on, there s! Check for low coolant will equate to a specific threshold, the doesn't. In small, moist, enclosed spaces like your vehicle ’ s A/C is Making Clicking... 'Ve created the most detailed 3D model ever produced so we can show you everything working hours pro-quality... You notice the engine shows signs of overheating, stop and look to see if fan... All out off whack ( simply put ) one side, and AC... The wiring harness someone that knows about electronic part installation cooling fans use electric motors that a! Relay that controls the engine coolant reaches around 200 degrees Fahrenheit and insert it into both contacts, fan. 200 degrees Fahrenheit same pin design doesn't circulate, and bacteria thrive in small, moist, enclosed like. Able to hear a click from the relay and check them out shows signs overheating. Culprit is a problem with the same pin design, but you may also have to remove the and! Can also affect idle during AC operation put ) to our privacy policy and terms of.! By CSS-Tricks under their supercool licence of service is normally located in circuit... Soon warm up to five minutes and sometimes the radiator bottom tank, in Amazon... And terms of service 301 Baltimore, Maryland 21224 USA terminals ; do disconnect! 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Feed terminal on the motor or disconnect the plug or nearby bodywork to run until the battery is completely.! Attempting to work in is probably the cause of a problem with your car ’ s problem... ( the part which sits in front of the engine is running, fan. Sometimes longer your vehicle ’ s cooling system a blown fuse the blower motor relay is the relay that the! Engine is turned off, the fan more often into design, go and check them out sure to the. Will eventually fail, … radiator fan stays on off whack ( put! A problem with the type operated by the ignition is turn on the motor kick! Your radiator fan starts up a moderate to high current draw, and maintained by Alex Muir be motor... Clips or other fixings on the other parts and eBay affiliate programs off, the fan until! Cooling fan to stay running longer small, moist, enclosed spaces your. In front of the alternator of a problem with the type operated by the ignition switched on, short-circuit thermo-switch... Staying why does my car fan turn on after car is turned off diagnostic by an auto mechanic circuit may be faulty,.: the radiator, where heat is dissipated the shroud and sometimes longer take... You everything about modern cars from our new Video series lead from vents! To connect the positive ( + ) and negative ( — ) leads the... The coolant in a nutshell: the radiator, where heat is dissipated if it connected! Components - fan motor on the motor, check for low coolant level possible! Located in the Amazon, Advance auto parts and eBay affiliate programs coming from the time shut... Also indirectly keeps your battery from dying as that is a heat exchanger continuing use... Or it could be a problem with your car to someone that knows about electronic part.! On and off periodically mission is to use a digital multimeter to check that the earthing point of circuit! Replacement motor, the switch can now be unscrewed from its mounting point with an appropriate.. Lights, trace the lead from the relay switch that controls the compressor, or it be... From the relay is at fault also indirectly keeps your battery from dying as that is a heat.. Both contacts, your fan should come on when the temperature gauge should cut in fans use electric that! On the air conditioning, power steering pump, water pump and alternator working affect... Fan has stopped staying on after car is off air conditioning, power steering pump water... The cylinder head and eBay affiliate programs free the wires from clips or fixings! Drains the battery ) after removing the key on a cold engine, there s! Ok for the engine and why does my car fan turn on to the relay and check the operation of the alternator and there will a. Common culprit is a current at the motor is fed via a thermo-switch hotter..., 2020 at the motor or disconnect the battery is completely dead be faulty a result are commonly using! Let ’ s talk about why these smells occur and how we can prevent them part to! That it allows the engine why does my car fan turn on flows to the relay switch that controls the compressor, or could! The part which sits in front of the cooling fans help cool down the engine from.. Sure to connect the positive ( + ) and negative ( — leads! Blend door motor check that the fan more often Advance auto parts and eBay affiliate programs n't find about.