Check that the radiator cooling fan comes on when the A/C is turned on. costs, Hand-picked, community-rated professionals, Explore nationwide job opportunities for automotive Have a 2004 WRX w/about 133,000 miles on it. 43 Posts . The temp. 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. YourMechanic All rights reserved. This is pretty much an open and shut case for a bad radiator fan relay, right? The trigger usually is a sensor, either monted on radiator or thermostat housing. 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. Fans kick on when AC is turned on. When the engine reaches operating temperature, the computer takes control with readings from the main sensors, and adjusts for the most efficient mixture. Thermostat. I plan to investigate my fans when I have it all back together. Hello there, a couple of different items can cause the fan to not work like this. 3. 2003 Acura RSX Type-S. Had the radiator, radiator fan, condenser fan, and thermostat replaced about 6 months ago with no issues. 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 what cause this? 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. Engine runs correct temp while air flows through radiator at highway speed or when AC is turned on (thus fan is on). For the meantime, search "zetec cooling fans-do not run" on the forums here. Yesterday i looked down and noticed the temp gauge at 3/4 of the way up. If the vehicle overheats, care should be taken when driving to prevent further damage by overheating. I don't know which one is the radiator fand and which one is the condenser fan since I can't find the condenser. Also the Fan may be on continuously when the AC is operating. document.write(new Date().getFullYear()) Please help Radiator electric fan has a trigger, apart from A/C compressor switch. The first thing you need to determine is if it is the clutch that is making the noise or the compressor. When the AC is off the fan does not turn on. I decided not to use the AC yesterday and the temperature gauge rose up. I see in the service manual that this does happen, but it does not tell me how to diagnose. 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. But the engine fan will come on only when the computer tells it to. If the switch was bad, though, wouldn't it not come on at all? Please advice. One Fan Engagement. I may have the wrong idea about what a fan switch does, though. The body control module gets signals from... Hey there. Discussion Starter • #1 • Jul 3, 2014. my 2001 hyundai accent has a problem.. it only turns on when the fan is unplugged from the sensor. 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. Cookies help us deliver our Services. 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. Made with ♥ in Silicon Valley. Press question mark to learn the rest of the keyboard shortcuts. thanks for help!! The engine fan shouldn't come on right away because the goal is for the car to warm up as soon as possible. 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. 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. Turning on the AC automatically turns on the radiator fans, hot or not hot. Most likely the temperature sensor that operates the fan under normal circumstances is faulty. The faster the car warms up the faster the Cat converter starts working. . One note on the fans. 1) Its ok, but neednt cut in immediate also. technicians, Trusted mechanics, rated by thousands of happy car The two engine fans are controlled by separate relays that are turned on by a powertrain control unit. I have to leave the AC on in order to get the radiator fans to run. In order for the AC Condensor to do its job it must stay as cool as it can. I think it has a radiator cooling fan issue. 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. 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. Anyway when I turn on the AC, only the one on the passenger side starts. In … Both the radiator fan and the condenser fan motor should run simultaneously. When When you engage your air conditioning in your car, it is usually summertime and hot outside. The problem began after I changed my timing belt and water pump for a third time. It's in the bottom of the radiator. The faster the engine is running the faster the fan will spin. A qualified technician, such as one from YourMechanic, will be able to diagnose your overheating problem and perform any repairs required. Turned the car off, let it cool, added coolant (roughly 1/4 gallon), and did some troubleshooting. 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. 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. Historically the temperature is in the middle of the temperature gage. Please see our. 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 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. Nzereogu kelechi. 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. The car has 229,000 miles. guides, Check cars for recalls, common issues & maintenance Toyota Camry 2004 radiator cooling fan only runs a few seconds while AC is on. Noticed recently that both radiator fans have been coming on more often and/or not turning off. 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. From the fuel pump to the engine, the lines run along the underside of your car. In other words, if the compressor runs the fan runs. If I don't turn on the AC, the temperature spikes to the yellow area. By using our Services or clicking I agree, you agree to our use of cookies. I have flushed the coolant to make sure there are no air bubbles and changed the thermostat. If your car has two fans and neither turns on, the problem is likely a blown fuse. 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. Hello there, a couple of different items can cause the fan to not work like this. The radiator fan switch is located on the thermostat housing and if jumped should operate the fans. 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. The system is controlled through the body control module that signals the powertrain control unit. Jump the two pins and see if the fan comes on. The radiator fan comes on when i turn the AC on (along with the condenser fan, of course). Turned the car off, let it cool, added coolant (roughly 1/4 gallon), and did some troubleshooting. Is the Cooling Fan Relay operating? When exactly this happens is different for different cars. 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. 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. 64 Posts . The ECT Switch may still be bad, even though the fan came on when you jumped it. Maybe a little bit slower, but it gets up to the red still. The AC fan should start when you turn on the AC. The fuel pump on your vehicle mounts underneath your back seat. 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? However, by running the AC I’m able to manually turn the fans on, yet even then it still overheats. When the AC is on the radiator fan works normally. You can replace the fan with a new unit. 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. ! Broken or shorter signal wire 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. 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. The most likely culprits are a thermostatic switch, fan resistor, temperature switch, low-speed or high-speed relay, or a wiring issue. If your A/C system smells bad check for mildew in the vents or install a new air filter. The fan fuse can be located in either the in-cab fuse box or the under-hood box. The higher the pressure the higher the … The blower resistor will... Oil and filter change intervals are specified by vehicle manufacturers, not mechanics, in carefully considered and prepared "maintenance schedules". Probably a bad fan switch. Does Running My AC in the Summer Keep My Engine Cooler. 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 … Radiator fan might wait even longer for the coolant to reach a certain temperature. If the vehicle overheats, care should be taken when driving to prevent further damage by overheating. It's toyota camry 2004 XLE 4 cylinder. 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. Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing. 18 September, 2019 Reply . When switch off the car and restart all gets fine again. 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. When on high, the circuit bypasses the blower resistor. 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. 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 … My car has a manual transmission. If you find that your vehicle is not cooling off properly, the radiator fan might be the culprit. 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. Electric Radiator fans do not come on when engine is hot nor after turning off, will only come on when AC is turned on. When temp gets to above 200 as noted by my diagnostic tool, fans do not turn on. why the radiator fan only turns on when i turn the a/c? Simply the engine is not hot enough to turn on the cooling fan, its not hot enough outside, you are driving getting … 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. If I manually start the driver side fan by spinning the blade with my finger, it then runs (AC still on). Yes 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. 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. Discussion Starter • #1 • Nov 16, 2012. © This actually led to a head gasket issue that I'm in the middle of now. 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. It seems like a sensor problem to me. If the compressor doesn't run the fan doesn't run. 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. 2 Answers. Just trying to be certain all is well as I had begun this journey by first replacing the VCRM module which had failed. I thought that if the switch was bad the fan would not come on at all. If I unplug the ECT sensor or turn the AC on, the fans will run, otherwise they won't kick in on their own. My car has 180502 miles. This unit spins when the engine is running, and it always spins at the same rate as the engine. Check/replace the Engine Coolant Temperature (ECT) Switch, not the ECT Sensor. The most likely culprits are a thermostatic switch, fan resistor, temperature switch, low-speed or high-speed relay, or a wiring issue. Everything seems fine. teamman: Please my 1997 Honda accord radiator fans only work when AC is on. 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. 190 Thermostat and coolant temp sensor are new.