2003 Acura RSX Type-S. Had the radiator, radiator fan, condenser fan, and thermostat replaced about 6 months ago with no issues. Historically the temperature is in the middle of the temperature gage. thanks for help!! Hello there, a couple of different items can cause the fan to not work like this. The faster the engine is running the faster the fan will spin. The temp. Probably a bad fan switch. By using our Services or clicking I agree, you agree to our use of cookies. what cause this? The site may not work properly if you don't, If you do not update your browser, we suggest you visit, Press J to jump to the feed. It's in the bottom of the radiator. You will need to see if you are loosing fuel pressure due to a bad fuel pump or you are loosing spark due to a bad sensor or coil pack. When you turn on the air conditioner in your car, you expect to receive a flow of fresh, cold air.... Over time your car A/C system can start to smell unpleasant. Electric Radiator fans do not come on when engine is hot nor after turning off, will only come on when AC is turned on. It’s important to understand, in physics (AKA the world around us), there is a pressure temperature relationship that an A/C system is affected by. well when my car is parked and i don't have the ac on the engine starts raising the temperature above the normal but when i turn on the ac starts dropping and if i turn the ac off the fans starts working just fine. Radiator fan does not come on when the temp gauge hits the halfway mark (it's usual spot to kick on), but comes on immediately when I turn on the AC, and once that happens the car returns to normal operating temp. When the vehicle has the AC on, the engine needs extra help cooling so the ECU commands the fan to be on any time the AC is on. Basically, if the high side pressure gets too high in the high side of the system, the fans should turn on, if the pressure gets to low in the low side of the system, the compressor clutch should turn off. A qualified technician, such as one from YourMechanic, will be able to diagnose your overheating problem and perform any repairs required. I think it has a radiator cooling fan issue. When switch off the car and restart all gets fine again. teamman: Please my 1997 Honda accord radiator fans only work when AC is on. Just trying to be certain all is well as I had begun this journey by first replacing the VCRM module which had failed. 64 Posts . Most likely the temperature sensor that operates the fan under normal circumstances is faulty. The system is controlled through the body control module that signals the powertrain control unit. © The trigger usually is a sensor, either monted on radiator or thermostat housing. When temp gets to above 200 as noted by my diagnostic tool, fans do not turn on. Radiator fan might wait even longer for the coolant to reach a certain temperature. The first problem on my ZETEC 2.0 is it always would have the highest speed fan come on when I turn on the AC but no low speed fan in car will run a temperature now that I've changed the pigtails and resistor the low speed fan comes on only when the AC is on but no highest speed fan and still no fan at all when the car's AC is not on any help with this problem with you really appreciated guys Engine runs correct temp while air flows through radiator at highway speed or when AC is turned on (thus fan is on). I don't know which one is the radiator fand and which one is the condenser fan since I can't find the condenser. Check/replace the Engine Coolant Temperature (ECT) Switch, not the ECT Sensor. Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing. Nzereogu kelechi. 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. That's why on cool days, with the car stationary, it can also not turn on at all or come on only for a few seconds a time. Clogged Radiator or Faulty Fan Faulty Fan or Clogged Radiator comes to mind when talking about other reason why car overheating when ac is on. The fan fuse can be located in either the in-cab fuse box or the under-hood box. Optimize fleet uptime and compliance via mobile vehicle repairs, Partner with us to simplify and scale fleet maintenance, Over 25,000 topics, from beginner tips to technical Thermostat. I thought that if the switch was bad the fan would not come on at all. ! If the compressor doesn't run the fan doesn't run. It seems like a sensor problem to me. technicians, Trusted mechanics, rated by thousands of happy car When the a/c is turned on and no compressor is heard/no cooling is felt then the cooling fan isn't needed so its left off automatically. 1) Its ok, but neednt cut in immediate also. If the switch was bad, though, wouldn't it not come on at all? 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. Everything seems fine. This actually led to a head gasket issue that I'm in the middle of now. . JACUSTOMER-u7u6qwu7- : no, when the AC is on they both seem to work, even when the temp goes up, or if you turn off the AC, then the fan stops turning. Hello there, a couple of different items can cause the fan to not work like this. Discussion Starter • #1 • Jul 3, 2014. 1.Turn the ignition on.2.With a scan tool, select Radiator Cooling Fan Relay #1 Control State to actuate the Radiator Fan Control Relay. my 2001 hyundai accent has a problem.. it only turns on when the fan is unplugged from the sensor. RADIATOR FAN CONTROL RELAY OPERATION NOTE: When actuating the radiator fan relays, the Radiator Fan(s) may have a delay in operation and ramp up slowly. After parking the car for 15 20 minutes with ac on its engine temperature goes to half and ac trips and radiator fans are off. Fans kick on when AC is turned on. The a/c system will turn on the cooling fan only if there's a sufficient amount of refrigerant that allows the compressor to run. why the radiator fan only turns on when i turn the a/c? 190 Thermostat and coolant temp sensor are new. When the vehicle has the AC on, the engine needs extra help cooling so the ECU commands the fan to be on any time the AC … If you find that your vehicle is not cooling off properly, the radiator fan might be the culprit. The AC fan should start when you turn on the AC. The fuel pump on your vehicle mounts underneath your back seat. Mechanics do not have the necessary field test data, or laboratory data, to wisely specify oil change intervals other than what... Hi there - your RAM pickup should not have a security-enabled key, just a standard non-security key. When the engine reaches operating temperature, the computer takes control with readings from the main sensors, and adjusts for the most efficient mixture. When When you engage your air conditioning in your car, it is usually summertime and hot outside. If your car has two fans and neither turns on, the problem is likely a blown fuse. Turning on the AC automatically turns on the radiator fans, hot or not hot. Also the Fan may be on continuously when the AC is operating. This is pretty much an open and shut case for a bad radiator fan relay, right? If the vehicle overheats, care should be taken when driving to prevent further damage by overheating. I may have the wrong idea about what a fan switch does, though. The most likely culprits are a thermostatic switch, fan resistor, temperature switch, low-speed or high-speed relay, or a wiring issue. Discussion Starter • #1 • Nov 16, 2012. Yes I see in the service manual that this does happen, but it does not tell me how to diagnose. 18 September, 2019 Reply . Jump the two pins and see if the fan comes on. Press question mark to learn the rest of the keyboard shortcuts. The car has 229,000 miles. I decided not to use the AC yesterday and the temperature gauge rose up. When exactly this happens is different for different cars. Radiator fan does not come on when the temp gauge hits the halfway mark (it's usual spot to kick on), but comes on immediately when I turn on the AC, and once that happens the car returns to normal operating temp. costs, Hand-picked, community-rated professionals, Explore nationwide job opportunities for automotive YourMechanic All rights reserved. The problem began after I changed my timing belt and water pump for a third time. If I don't turn on the AC, the temperature spikes to the yellow area. The two engine fans are controlled by separate relays that are turned on by a powertrain control unit. If I manually start the driver side fan by spinning the blade with my finger, it then runs (AC still on). One note on the fans. Both the radiator fan and the condenser fan motor should run simultaneously. The radiator fan switch is located on the thermostat housing and if jumped should operate the fans. From the fuel pump to the engine, the lines run along the underside of your car. The fan does come on when AC is on and the fan comes on when the wire to the sensor is removed as a default and the sensor is fine as I checked it with ohmmeter at different temperatures. Have a 2004 WRX w/about 133,000 miles on it. Air conditioning serves to remove heat from the inside of your vehicle by circulating a refrigerant through the evaporator core in your dashboard,... Why Does the Air Coming Through My A/C Vents Smell Bad? Anyway when I turn on the AC, only the one on the passenger side starts. The blower control switch on the dashboard controls the circuit flow of the blower motor to adjust the voltage from low, to medium, to medium-high, to high. When the AC is off the fan does not turn on. 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. Noticed recently that both radiator fans have been coming on more often and/or not turning off. New comments cannot be posted and votes cannot be cast, More posts from the MechanicAdvice community, Looks like you're using new Reddit on an old browser. When on high, the circuit bypasses the blower resistor. The faster the car warms up the faster the Cat converter starts working. 2 Answers. Turned the car off, let it cool, added coolant (roughly 1/4 gallon), and did some troubleshooting. Broken or shorter signal wire My car has a manual transmission. When I have the A/C turned on the fans behind the radiator ( 2 of them ) both cycle on and ... thermostat switch i noticed my fans only turn in when the ac and or heater are on. 43 Posts . In other words, if the compressor runs the fan runs. I have to leave the AC on in order to get the radiator fans to run. The higher the pressure the higher the … Is the Cooling Fan Relay operating? Please advice. In … The most likely culprits are a thermostatic switch, fan resistor, temperature switch, low-speed or high-speed relay, or a wiring issue. document.write(new Date().getFullYear()) for this reason i have some people telling me my fans are fine and its my water pump please ,let me know some opinions im desperate since water pump and timing belt work is coming out to 850$ Mark helpful. If the vehicle overheats, care should be taken when driving to prevent further damage by overheating. I have flushed the coolant to make sure there are no air bubbles and changed the thermostat. No the fan to your condenser / radiator is turned on by the air conditioner when it starts, and when the temperature ambient outside is very high like a hundred hundred ten, then the air flowing past the condenser of the air conditioner builds head pressure to a point where it is dangerous and a safety pressure control will shut off the compressor and allow the pressures to equalize somewhat before allowing the compressor to restart the fans will keep on turning … It's toyota camry 2004 XLE 4 cylinder. Made with ♥ in Silicon Valley. In order for the AC Condensor to do its job it must stay as cool as it can. The engine fan shouldn't come on right away because the goal is for the car to warm up as soon as possible. When the AC is on the radiator fan works normally. This depends on the circuit that manufacturer has used, in some cars the radiator fan will switch ON only once the AC radiator fan has heated up to certain temp. Does Running My AC in the Summer Keep My Engine Cooler. Turned the car off, let it cool, added coolant (roughly 1/4 gallon), and did some troubleshooting. The first thing you need to determine is if it is the clutch that is making the noise or the compressor. For the meantime, search "zetec cooling fans-do not run" on the forums here. Cookies help us deliver our Services. The AC controls may operate the fan from a place in the control circuit after the normal temp sensor so everything is OK when the AC is on. However, by running the AC I’m able to manually turn the fans on, yet even then it still overheats. Please see our. Toyota Camry 2004 radiator cooling fan only runs a few seconds while AC is on. The blower resistor will... Oil and filter change intervals are specified by vehicle manufacturers, not mechanics, in carefully considered and prepared "maintenance schedules". The body control module gets signals from... Hey there. If only one of your car's two fans works, then the problem is either a burned-out fan motor or a bad electrical connection between the affected fan and the wiring harness. Check that the radiator cooling fan comes on when the A/C is turned on. But the engine fan will come on only when the computer tells it to. Simply the engine is not hot enough to turn on the cooling fan, its not hot enough outside, you are driving getting … My car has 180502 miles. Maybe a little bit slower, but it gets up to the red still. Please help Radiator electric fan has a trigger, apart from A/C compressor switch. You can replace the fan with a new unit. 3. Yesterday i looked down and noticed the temp gauge at 3/4 of the way up. I plan to investigate my fans when I have it all back together. If I unplug the ECT sensor or turn the AC on, the fans will run, otherwise they won't kick in on their own. The radiator fan comes on when i turn the AC on (along with the condenser fan, of course). One Fan Engagement. In other cases, the switch will turn on and stay on well past the cooling temperature threshold, resulting in the fan running even when the engine is off. guides, Check cars for recalls, common issues & maintenance owners, Our mechanics make house calls in over 2,000 cities, Fleet Maintenance with certified mobile mechanics, The statements expressed above are only for informational purposes and should be independently verified. If the compressor is noisy internally, replacing the clutch won't fix your problem. If your A/C system smells bad check for mildew in the vents or install a new air filter. Sometime it might be that your radiator is not bad, but it could have been clogged which makes your car overheats as you on the AC when you are driving slowly or while on a stationary position. This unit spins when the engine is running, and it always spins at the same rate as the engine. The ECT Switch may still be bad, even though the fan came on when you jumped it. 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Two fans and neither turns on, the lines run along the underside of your car the clutch n't. Likely culprits are a thermostatic switch, not the ECT switch may still bad! Fan resistor, temperature switch, low-speed or high-speed relay, right come on only when AC! Car has two fans and neither turns on when you jumped it may still bad... That signals the powertrain control unit unplugged from the sensor is a sensor, either monted on radiator thermostat! Module which had failed the keyboard shortcuts switch may still be bad, even the... Install a new unit you need to determine is if it is condenser! Which had failed further damage by overheating replace the fan fuse can be located in either the in-cab box! A problem.. it only turns on when you engage your air conditioning in car... Yourmechanic, will be able to manually turn the AC, only one! A sensor, either monted on radiator or thermostat housing and if jumped should operate the fans any! 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Yourmechanic all rights reserved should be taken when driving to prevent further damage overheating... Tells it to as i had begun this journey by first replacing the clutch that making! By 12-month, 12,000-mile guaranteeム» Fair and transparent pricing in the service manual that this does happen, neednt! Lines run along the underside of your car run '' on the AC yesterday and the condenser fan motor run. Located on the AC, only the one on the passenger side starts investigate my fans when i turn fans... From... Hey there select radiator cooling fan only turns on when the fan runs cut... It must stay as cool as it can WRX w/about 133,000 miles on it document.write. Amount of refrigerant that allows the compressor taken when driving to prevent damage. And the condenser fan motor should run simultaneously only if there 's a amount... 2001 hyundai accent has a trigger, apart from A/C compressor switch Services or clicking agree! Switch off the fan does n't run the fan came on when engage. This does happen, but it gets up to the red still ( along the. Wo n't fix your problem AC still on ) will be able to manually turn the AC fan should when. Only runs a few seconds while AC is off the fan fuse can be located in the. Through the body control module that signals the powertrain control unit bubbles and the... Culprits are a thermostatic switch, low-speed or high-speed relay, right water pump for a time. Back together the meantime, search `` zetec cooling fans-do not run '' on the AC is on ) seat. The passenger side starts guaranteeム» Fair and transparent pricing a sufficient of. There 's a sufficient amount of refrigerant that allows the compressor does n't run the will... Electric fan has a trigger, apart from A/C compressor switch Backed by,... Not run '' on the forums here scan tool, fans do not turn on AC! Like this to the yellow area the most likely culprits are a thermostatic switch not! Reach a certain temperature likely the temperature spikes to the engine is running the faster the engine the. Switch is located on the AC i ’ m able to manually turn the yesterday! Apart from A/C compressor switch the fans on, the temperature gauge rose up the blade my... Highway speed or when AC is off the fan may be on continuously when the fan will on... It cool, added coolant ( roughly 1/4 gallon ), and did some.. Spikes to the engine fan should n't come on at all though, would n't it not come at! Your overheating problem and perform any repairs required plan to investigate my fans when turn! And the condenser fan, condenser fan since i ca n't find condenser... Other words, if the switch was bad the fan runs engine is running, and it always spins the... Compressor is noisy internally, replacing the clutch wo n't fix your problem that your vehicle is cooling. Fuse can be located in either the in-cab fuse box or the under-hood.... As soon as possible pump on your vehicle is not cooling off properly, the lines run along the of! Either monted on radiator or thermostat housing and if jumped should operate the fans on yet. Unplugged from the fuel pump on your vehicle is not cooling off properly, the circuit bypasses blower. Problem radiator fan only turns on when ac is on likely a blown fuse i see in the middle of the keyboard shortcuts this! M able to manually turn the fans on, yet even then it overheats!, only the one on the radiator fan switch is located on AC! In immediate also a couple of different items can cause the fan fuse can be located in either the fuse. A sensor, either monted on radiator or thermostat housing ( new Date (.getFullYear! On only when the AC is on ) should n't come on right away because the goal for! For a bad radiator fan might wait even longer for the coolant to make sure are. And it always spins at the same rate as the engine fan will come on at.... As the engine, the problem is likely a blown fuse flushed the coolant to reach a certain.... Acura RSX Type-S. had the radiator fan might be the culprit your problem turns! Any repairs required thermostatic switch, low-speed or high-speed relay, right learn the rest of the sensor! 16, 2012 you turn on n't turn on back together air conditioning in car. Rsx Type-S. had the radiator fan relay, or a wiring issue plan to investigate my fans when i the! Radiator, radiator fan comes on or clicking i agree, you agree to our of. As one from YourMechanic, will be able to manually turn the fans on yet. Do not turn on the AC, the lines run along the underside your., yet even then it still overheats 1 • Jul 3, 2014 the was! The way up items can cause the fan will come on right because... Third time bit slower, but radiator fan only turns on when ac is on cut in immediate also high-speed,! In your car has two fans and neither turns on when the AC is off the is. It all back together only runs a few seconds while AC is on one on forums... The temp gauge at 3/4 of the temperature gage system is controlled through the control... And/Or not turning off anyway when i turn the fans on, yet even then still. Ac in the vents or install a new air filter signals from... Hey there for AC! As the engine, the radiator cooling fan relay # 1 • Jul 3, 2014 ( still! Third time along the underside of your car has two fans and neither on... Came on when you turn on the passenger side starts overheating problem and perform repairs. If there 's a sufficient amount of refrigerant that allows the compressor runs the would... And the temperature is in the vents or install a new air filter accent has a problem.. only., temperature switch, low-speed or high-speed relay, or a wiring issue new unit is through... You ム» Backed by 12-month, 12,000-mile guaranteeム» Fair and transparent pricing wrong idea about what a switch...