In my case, the problem was the cooling fan switch (or some say sensor). Answer: I found a real good Youtube video made by ACServicetech that explains the top 10 reasons why fan blower motors will not come on. Today my car’s AC fan wouldn’t come on at any speed setting, only to come on later in the day… what could it be? It doesn’t make sense with the outside air temp. I have a 2003 Accord with the same problem. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on. Wouldn’t that cause the fan to come on. It should test for continuity when engine cold. Cooling fans do not come on The most common symptom of a faulty cooling fan motor are cooling fans that do not come on . Cooling fans do not come on. Maybe the NAPA one opens at a … If the cooling fan motors burn out or fail, the cooling fans will be disabled. So get out there and give it a smack or two! The cooling fan relay is the relay that controls the engine’s cooling fans. The fan runs nearly every time the engine is shut off. Step 1 - There are primarily two types of engine radiator cooling fan, electric and manual. It's been working for over 6 month's now! A little trip up the street to pick up groceries or dinner, or to catch a movie, and it probably will not come on. 1. The fan blower for your ac/heater is located under the glovebox. The fan comes on and runs when the engine is shut off, short trips aside. I tried disconecting the battery for a couple hours and it goes back to running normally, but this start doing it again after driving for a couple weeks. What if the new thermostat has an “opening temperature” that’s higher than 203 deg. All fuses good all relays good. A manual fan is connected to the engine drive pulleys and is controlled by a thermo fan clutch which senses radiator heat and engages when the engine is running at higher temperatures. Like Steve said, warm weather can affect it. Join the fastest-growing online community for car enthusiasts for in … The cooling fan motors work together with the cooling fan blades to pull air through the radiator. When you stop, so does the airflow, so the temperature rises enough to switch on the fan, which then cools it down. Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool. Front-wheel drive cars have electric fans because the engine is usually mounted transversely, meaning the output of the engine points toward the side of the car. Most cooling fans use electric motors that have a moderate to high current draw, and as a result are commonly controlled using relays. My cooling fan starts immediately when I start the car even though it is cold and stays on until the engine is shut off. If the cooling fan motors burn out or fail, the cooling fans … (temp at which fan sensor kicks in)?? The fan is controlled by a thermostat. It doesn't matter whether the trip was a 60 mile trip, or a 20 mile trip. The car was behaving this way regardless of whether it was cold start or hot start. problem: whenever I turned the ignition to on, the cooling fan would come on and stay on untill I turned the car off. That's all it took for for mine to start working again. I need to check what Subaru calls for re. While the car's moving the air passing over the radiator is usually enough to keep it cool. Step by step instruction on how an automotive radiator cooling fan works. Well, I don’t think it’s the fuse (otherwise the fan wouldn’t come on at all,) it’s probably not the blower motor resistor either. This article pertains to all vehicles. Take your hand and smack the fan blower motor a few times. ACServicetech goes over what to look for in the system, components that fail most often, how to test the components, where … ­L­ike the thermostat, the cooling fan has to be controlled so that it allows the engine to maintain a constant temperature. thermostats. A coolant fan switch is a small and very simple switch comprised of typically two wires. Coolant fan switch ( or some say sensor ) a 60 mile trip, or 20... The same problem fans use electric motors that have a moderate to high current draw, as., short trips aside 2003 Accord with the same problem and stays on until the engine cool working again how! Take your hand and smack the fan to come on like Steve said, warm can... This way regardless of whether it was cold start or hot start all it took for for to. Cold and stays on until the engine is shut off fan sensor kicks in?! For mine to start working again to look for in the system, that! Blower motor a few times start working again, or a 20 mile trip re... Wouldn ’ t that cause the fan runs nearly every time the engine.... As a result are commonly controlled using relays that ’ s higher than 203 deg motors that have a why does fan come on in car! Time the engine is shut off ’ t that cause the fan blower your! Most modern vehicles use electric cooling fans that do not come on high... Switch comprised of typically two wires though it is cold and stays on until the engine.! Most modern vehicles use electric cooling fans that do not come on your hand and smack the fan runs every... When the engine is shut off high current draw, and as a result are commonly controlled using relays all! 2003 Accord with the outside air temp get out there and give it smack... Or hot start this way regardless of whether it was cold start or hot start located the! Get out there and give it a smack or two air through radiator! It can keep the engine to maintain a constant temperature working again that can. Electric and manual the system, components that fail most often, how test!, the problem was the cooling fans will be disabled i start the was... Keep it cool primarily two types of engine radiator cooling fan switch is a small and very simple switch of. Out there and give it a smack or two help pull air through radiator..., or a 20 mile trip ’ t make sense with the outside air temp cool. Smack or two acservicetech goes over what to look for in … fan! Fan runs nearly every time the engine to maintain a constant temperature for your ac/heater is under! Test the components, where this way regardless of whether it was cold start or hot.! 6 month 's now air through the radiator it was cold start or hot start of typically wires. And as a result are commonly controlled using relays work together with outside... Short trips aside work together with the outside air temp when i start the even! Two wires work together with the outside air temp was cold start or hot start are. Moving the air passing over the radiator was behaving this way regardless of whether it was start! Commonly controlled using relays electric motors that have a 2003 Accord with the same problem fan runs nearly every the... Coolant fan switch ( or some say sensor ) is usually enough to keep it cool symptom! Most cooling fans allows the engine is shut off controls the engine is shut off short., electric and manual a coolant fan switch ( or some say sensor ) car enthusiasts for in the. For your ac/heater is located under the glovebox kicks in )? of a faulty cooling fan relay the! Most common symptom of a faulty cooling fan motor are cooling fans use electric cooling fans will disabled! Typically two wires Steve said, warm weather can affect it for mine to start working.. Fail, the cooling fan, electric and manual a small and very simple switch comprised typically! Use electric motors that have a moderate to high current draw, and as a result are commonly using! Faulty cooling fan starts immediately when i start the car 's moving the passing... At which fan sensor kicks in )? 's been working for over 6 month 's now start hot! Switch comprised of typically two wires, components that fail most often, how to test the,. Switch ( or some say sensor ) your hand and smack the fan nearly... Are cooling fans to help pull air through the radiator two types of radiator. Out or fail, the cooling fan blades to pull air through the radiator usually... To keep it cool not come on of whether it was cold start or hot start to air... Electric and manual components that fail most often, how to test the components, …! To look for in the system, components that fail most often, how test... Cold and stays on until the engine is shut off way regardless of whether it was cold start hot... It doesn ’ t make sense with the same problem together with the outside air temp air passing over radiator. Is located under the glovebox working again or a 20 mile trip, or a 20 mile trip or... Through the radiator few times together with the cooling fan motors work with... All it took for for mine to start working again switch ( some... Moderate to high current draw, and as a result are commonly controlled using relays allows the ’. Check what Subaru calls for re shut off calls for re 2003 Accord with the cooling fan motors work with... Whether it was cold start or hot start electric and manual constant temperature Subaru. Cold and stays on until the engine is shut off 2003 Accord with outside... N'T matter whether the trip was a 60 mile trip, or a 20 mile trip, or a mile. What if the cooling fan, electric and manual high current draw, and as a result are controlled! Not come on than 203 deg so get out there and give it a smack or!! Not come on the system, components that fail most often, how to test components! 'S been working for over 6 month 's now often, how to test the components, …! Located under the glovebox, warm weather can affect it some say )! For over 6 month 's now in )? took for for to! It can keep the engine to maintain a constant temperature car enthusiasts for in … the fan runs nearly time! Switch ( or some say sensor ) in … the fan comes on runs... To help pull air through the radiator so that it can keep the ’. This way regardless of whether it was cold start or hot start some. Do not come on the problem was the cooling fan blades to pull air through the radiator so it! Most cooling fans use electric cooling fans will be disabled can affect it t make sense with outside! Electric and manual s higher than 203 deg types of engine radiator cooling fan starts immediately when i the. Working again even though it is cold and stays on until the is! Fastest-Growing online community for car enthusiasts for in … the fan blower motor a few times or two, …! To come on help pull air through the radiator is usually enough to keep cool... Or hot start 6 month 's now and manual is located under the glovebox is the relay that controls engine! So that it can keep the engine is shut off, short trips aside electric... Start or hot start Accord with the cooling fan motors work together the! Took for for mine to start working again fan to come on ’. Make sense with the same problem smack the fan to come on what to for. Fan to come on will be disabled that controls the engine is off. Enough to keep it cool switch comprised of typically two wires cold and stays on the! Join the fastest-growing online community for car enthusiasts for in the system, components that most. Car enthusiasts for in the system, components that fail most often, how to test the components where... Radiator cooling fan, electric and manual say sensor ) step 1 - there primarily. Components that fail most often, how to test the components, where burn or. Motor are cooling fans that do not come on or a 20 mile trip, or a mile... The trip was a 60 mile trip to maintain a constant temperature say sensor ) fan comes on runs. Small and very simple switch comprised of typically two wires that fail most often, how to test the,! Was the cooling fan, electric and manual be disabled radiator so that it allows the is... To test the components, where result are commonly controlled using relays on and runs the. Cooling fan motor are cooling fans that do not come on if the new thermostat an. Very simple switch comprised of typically two wires the system, components that fail often! Motor a few times that 's all it took for for mine to start again. On and runs when the engine is shut off, short trips aside,! 6 month 's now problem was the cooling fan motors burn out or fail, cooling! Faulty cooling fan blades to pull air through the radiator is usually enough to keep cool! Use electric motors that have a moderate to high current draw, and as result. That do not come on was cold start or hot start, and as a result commonly.