In my case, the problem was the cooling fan switch (or some say sensor). The green wire goes to fan relay 1 have a pro check this by scanning as it may be something else all together like a thermistor or control head for hvac. The cooling fan just stays on. Mine does the same at times but hasn't in awhile. The electric cooling radiator fan, which turns on and off as needed based on the internal vehicle temperature, is an improvement over engine-driven fans that slow down a usually when they are needed the most. VerticalScope Inc., 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1, Canada. The length of time cycling on and off seems to correlate to the temperature. The radiator fan turns on at cold startup. cjcoburn Member. As soon as I turn off my heater, the fan turns off. The radiator fan does a very important job; it cools the radiator to stop the car from overheating. The difference between these two kinds of fans can affect why the radiator fan turns on when the car starts. The mini copper fans should speed up the process of cooling by driving fresh air into the radiator. ******************************************************************************************************. There are typically a few locations where the problem is originating from, such as the fan motor, thermal switch, wire, or relay. Without these parts working at the optimal level, your vehicle will not be able to function and perform the way it is supposed to. 46 Posts . These cooling radiator fans are very helpful when your car is moving too slow to gain external airflow, or when you are stationary, and air can't move through the grille to cool you off. A forum community dedicated to BMW owners and enthusiasts. The A/C condenser (the part which sits in front of the coolant radiator) is a heat exchanger. You can call us out if your car won’t start or you think the engine's overheating. The mini copper fans should speed up the process of cooling by driving fresh air into the radiator. , is an improvement over engine-driven fans that slow down a usually when they are needed the most. I'll check and clean connections. One part of the car that is imperative to a smooth and safe ride is the radiator fan. Yes, the fan will come on when you turn the A/C on, so that proves the fan works. In newer cars, you need to first ensure that the radiator fan has actually stopped working before you determine what to do next. 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. I have read that is should turn on when the ac is turned on I would like to be reassured of this. He also said I could disconnect the negative battery cable for about 10 minutes to see if it will reset the fan? A radiator fan is imperative in keeping the coolant’s temperature low enough to keep the passengers comfortable. Then you notice the engine cooling fan is still running even though the car is turned off. If you can’t figure it out, take your car to a mechanic right away so he can determine the issue. Why does your Mini Cooper Fan stay on when I turn off the engine? is to keep the coolant at the right temperature so that when it travels back to the engine, it is able to take on more heat, and prevent the engine from getting too hot. This cycles on and off for about a few minutes. Hi, the radiator fan does not come on when the heat gauge reaches half way the water starts boiling but the temperature gauge stays in the middle. The fan still inst working, however if I unplug the temperature sensor the fan works from start up. It's never done this before, up until the last couple of weeks. In order to figure out the reasons why your radiator fan turns on when the car starts, you need to know how it works, the function of the radiator fan, and the signs of a failing radiator fan. Cadillac Transmission Repair Cost – Avoid The 2016 Cadillac ATS! You can always tell that something is wrong with your radiator fan not turning on when you start your car. Sure enough, about 45 min later the fan came back on and required the ignition to be switched on to turn it off. Coolant levels are at max cold level. In addition, there are other obvious signs of a bad or failing fan motor. All Rights Reserved. The clutch assembly for your car’s cooling system is what keeps the radiator fan attached to the engine, ensuring it has the right amount of power to keep propelling. Recently I noticed that after the car's been off for about 10-20 minutes, the radiator fan will start up and never stops on its own. The engine contains a combustion chamber where explosions take place to provide power and heat the car. First, you need to unplug the wiring connector. I was told that it was a faulty temperature sensor which I replaced. The radiator fan turns on at cold startup. Check for any damage and clean the connector to get rid of any debris or contaminants. Again, the HVAC is off. Looked everywhere and can't find anything about this. Also, the fan will do this even after short 5-10 minute trips. If your fan has still failed to turn on when the car starts, you can check the fan by connecting a power source to it. 2008 track model with about 18,000km. This cycles on and off for about a few minutes. As best I remember the idle does jump up when the A/C is on, but it does it the same way as when the radiator fan kicks-on: the idle drops low first (sometimes almost stalling for a moment) and then comes up to a bit higher than an idle without the A/C or radiator fan being on. Turn the air conditioning to the maximum setting – this should spark the cooling fan to immediately come on. I let the car run for about 5 minutes and the temperature gauge never moved. I checked all the relays and fuses. The cooling fan comes on when I start the car and stays on for 5 minutes after I turn it off. Does the radiator fan come on with AC? What's wrong with my cooling fan? The trigger is the thermostat in the radiator of your vehicle. The length of time cycling on and off seems to correlate to the temperature. The cooling system circulates a coolant through the engine that absorbs heat. If your car is running at a sub-par level, then there is a greater chance that other components can be negatively affected and lead to more repairs and replacements. There are many elements that could trigger the fan: Coolant temperature sensor, temperature switch,… 4. This is not after a … I am clueless where to go next. The fuse will blow to protect the rest of the system from further damage due to the unforeseen electrical surges. Second, look at the wires and identify which ones are power wires and which ones are ground wires to avoid any confusion. Amateur Diagnosis. Go. https://www.cashcarsbuyer.com/radiator-fan-turns-on-when-the-car-starts A sign of the wire link needing replacing is if your radiator fan fails to turn on when the car starts. turns on and off as needed based on the internal vehicle temperature. Knowing this key information can help you keep your radiator fan running efficiently for as long as possible. 2 Posts . That heated coolant then runs through the radiator, where the heat dissipates. JavaScript is disabled. In a nutshell: The radiator fan comes on so the A/C works at its highest efficiency. A failed radiator fan can result in overheating your engine. The electrical radiator fan is controlled by an electric motor, with the radiator fan turns on when the car starts. Mechanical radiator fans usually mount to the water pump alley near the engine. The fuse will blow to protect the rest of the system from further damage due to the unforeseen electrical surges. Hi, I have a 2007 GTI. If your cooling fan circuit fuse has blown, this is another sign of a problem with the radiator fan motors. Disconnect the Engine Coolant Temperature Sensor (ECT). If your motors fail or surge unexpectedly, then this can cause the fuse to blow. When I turn my car off, the fan stays on for a few minutes before turning off. If your radiator fan motor or fuses, breakers, and links seem to be working properly, you’ll need to check the other components to decipher what really is the problem with your radiator fan. If the fuse has gone, the mechanic will need to replace it right away. The low speed fan comes on at 224ºF. Thread starter cjcoburn; Start date Jul 4, 2017; Forums. When I turn my car off, the fan stays on for a few minutes before turning off. If the fan doesn’t come on, you need to look for a broken fuse or breaker. Anyways, the radiator fan turns on, and stays on, whenever my heater is switched on. Discussion Starter • #1 • Jul 22, 2015. 3. You might also find mechanical radiator fans more often in modern trucks and bigger vehicles. Did you find out what the cause of the fan going at high speed? 1 of 2 Go to page. Bringing the BMW community together. I've seen it run for 25 minutes until getting worried the battery would drain. The temperature switch in most vehicles is typically located by your car’s engine computer or your powertrain computer. Normally AC usually will heat up after you turn it on, and the air conditioning cooling system was set the reduce the heat. So when the cooling system starts to malfunction then will lead to car overheating when air conditioner is on. Car has about 75k-80k miles, and recently the fan started staying on after I turn the car off ( no matter how long the trip or the temp outside). EGR Valve Replacement – What You Need To Know! The. There is a fault code set in the engine computer that will cause it to operate in a failure mode in that it turns the fan on to be sure the engine will be cooled. The ECT needs to be viewed on a scan tool as well as some other DME parameters when engine is started cold. I also wanted to hear if it would happen again so I listened very closely for it. Avoid These 10 Bad Driving Habits That Could Ruin Your Engine. Your car fan will run for a few minutes after you turn off the car then turn … Radiator fans are designed to start when the temperature of the engine coolant reaches around 200 degrees Fahrenheit. Ok. @johnblack I checked it while it is on cold state, but then when turn the AC ON the Radiator Fan turn on, so I let the AC ON while i drive my car, after 30mins driving if i turn the AC OFF, the RADIATOR FAN still dont work, even the Radiator Temp was hot. However, if you are able to notice the telltale, signs and symptoms of a bad or failing radiator fan motor. Then you notice the engine cooling fan is still running even though the car is turned off. sensor, and radiator cup. If your coolant level is low there is a chance that you will get air in the system … this is another sign of a problem with the radiator fan motors. So, everytime I turn on my heater, a fan turns on from the engine bay. In addition, there are other obvious signs of a bad or failing fan motor. I was told that it was a faulty temperature sensor which I … A failed radiator fan can result in overheating your engine. The computer turns the cooling fan on and off when it receives a temperature indication from the coolant temperature sensor. The difference between these two kinds of fans can affect why the. This issue doesn't happen if engine is warm. The cooling fan motors are crucial to the cooling fan assembly and play a huge role in your car’s safety, keeping the correct temperatures while idling and at low speeds. The coolant fan will continue to run until the … The mechanic has told me that it only turns on when the ac reaches a certain pressure. It's never done this before, up until the last couple of weeks. My truck just … What causes the radiator fan to come on? They run from the time i turn the truck on to the time I shut it off. Leave the A/C off for the rest of the test. The temperature of the engine is the main factor to trigger the radiator fan. My car came to me with a new water pump, and I'm not getting any idrive or cel or codes, so I figured this may be a normal thing on these cars? As soon as I turn off my heater, the fan turns off. However, if you are able to notice the telltale signs and symptoms of a bad or failing radiator fan motor, you might be able to stop the problem before it gets worse. 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