Set your air conditioning to the MAX setting and turn it on. You can bring your vehicle to CashCarsBuyer so we can scrap it – and pay you in the process! 5. Ensure that the wires are firmly attached and are not damaged. If the compressor doesn't run the fan doesn't run. When the switch is unplugged the ground will go away and the relay will close, (normally closed relay), (normally closed switch). 2. All the relays and fuses have been tested, they seem ok. No success, I tried switching each of the three of them separately. Second, start the engine and start idling your vehicle. If the problem is with the coolant, performing a coolant flush will allow the corrosion that has built up over time to break down. Unpluging the connector and then the fans run, is the same thing as opening the circuit! They were fine. However, if there is an issue with the number of volts of electricity, then that usually means the wire needs to be replaced. With the AC on, it ran on high all the time, so the engine temp was actually below 200 with the AC on. Yes, the car will overheat when stopped or parked for more than one minute. If you don’t have resistance values, but you are able to deduct that the Ohms values remain the same during cold and hot temperatures, you should replace the sensor in order to fix your radiator fan. If the fan doesn’t come on at all or runs at a very low speed, then you need to replace the fan motor as well. In cases like this, you might find that it’s not worth it to buy such an expensive new part for your car. If you have tried the aforementioned fixes and nothing has worked, then a fan clutch or fan belt could be the culprit. If you can’t figure it out, take your car to a mechanic right away so he can determine the issue. If either does not run, it's the motor. Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. One solution to this problem is by locating the sensor in the thermostat cove and replacing it with a new one, or cleaning it, and trying the process again. If the fan comes on when the air conditioning is operating at maximum volume, but doesn’t run properly when the engine is warm or hot, then you might need to check the temperature switch. If the temperature sensor is broken, it won’t be able to transmit the signals at the proper time to the ECU – and the fan won’t turn on. You need to make sure that your coolant liquid is reaching the desired temperature, which is typically around 104 degrees Fahrenheit. The car has 229,000 miles. You may need to look at your vehicle repair manual to see if your vehicle has a 4-wire terminal or three terminals, with two for power and one for ground wires. Second, look at the wires and identify which ones are power wires and which ones are ground wires to avoid any confusion. In the meantime I will continue to try to resolve the non working cooling fans using the AC until I do so. 3. I lived with it for a year and now it's not coming in at all. Don't use bars leak it will stop up the radiator faster then eggs. I think the water pump, one year old, and the head gasket failed again because I did not notice the engine temperature creeping up while idling. AC does not work when temp rises.39642.564946412 … 3 people found this helpful. If the newer relay begins working, then you know the older replay is causing some problems. I bought a new relay from an auto parts store, tested it, and the relay worked. First, you need to unplug the wiring connector. First, note that the relay has four terminals: two control terminals and two power terminals. Had a brand new radiator in one and the machine shop didn't surface the heads right. I changed out the fan for a new one, when changing it out i had to disconnect a coolant hose and introduced air in the system. Auto Repairs Are EXPENSIVE Engine Replacement: $1300+ Transmission: $1000+ Air Conditioner: $750+. May be your problem. Head gasket could be the problem all together! Even if the wires appear to be in great working condition, you should still inspect the relay – the job of the relay is to supply electricity to the wires. See your "what's this wire for" thread for an explanation of the coolant temp sensor found in the radiator. Once the temp gets so hot, the ECU commands the radiator fan to come on. Despite a blown fuse not being a big issue, it is important to find and fix. Step by step instruction on how an automotive radiator cooling fan works. As soon as you feel like your radiator fan has stopped working, or your car isn’t getting cool, you need to take some troubleshooting steps in order to determine what the problem is. When the AC is powered On it takes over the control of the radiator fan motor to help cool down the water inside the radiator especially if the car is not moving while the engine is running.. © 2020 Cash Cars Buyer. After the engine has reached operating temperature, back probe the other wire at the connector. The temperature switch on most vehicles is typically connected to your car computer, or your powertrain computer. Thank you everyone and I will keep you posted of whatever my oversight has been. Thank you. Fortunately for you, the average cost of a radiator fan is not very expensive. Almost seems like it has got to be crud inside the radiator where this normally closed COOLING FAN SWITCH screws into and is not opening the switch circuit when the coolant reaches the correct tempture. On many modern vehicles, if you want to confirm whether your cooling fan is in working order, you can start the engine and let it idle. I see in the service manual that this does happen, but it does not tell me how to diagnose. Thank you for taking time out for this. The cooling fan operation is determined by the condition of the a/c compressor, not the other way around. No AC (but full with no leaks) 2. I did try the new one from Pep Boys that must also have been defective. If the radiator fan is not working correctly, your car can get damaged, and if you let it go too long without a repair, the fix can be thousands of dollars out of your pocket. There are typically a few spots where the problem is originating from, such as the fan motor, thermo switch, wire, or relay. Unpluging the connector and then the fans run, is the same thing as opening the circuit!! After all like you said just to get a few more miles out of it. Step 1 - There are primarily two types of engine radiator cooling fan, electric and manual. People often get confused about the cooling fan operation!! A coolant fan switch is a small and very simple switch comprised of typically two wires. However, if your car has coolant in it, but still overheating, then the problem might be with the radiator itself. No the AC will turn the radiator fan on to pull air across the condensor. If your coolant level is low, then it might not feel as if your car is getting cool, even with the radiator fan turned on and working. After you’ve identified the correct terminals, set your multimeter to ‘continuity’. Take the time to test relays before blindly changing them. The last case scenario when testing your radiator fan is when the fan doesn’t come on after the engine has been running for 20 minutes. If necessary, a replacement relay costs around $20.There are three ways to check for a bad terminal. The cooling fan should come on immediately or within the next couple of minutes. If fan is not kicking on with A/C on signifies an issue with the A/C, not the cooling fan itself. That piece was the first thing I replaced. The radiator is about two years old and the cooling system is clean. I have to leave the AC on in order to get the radiator fans to run. Coolant air bubble 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. determine if the fan relay is causing your radiator fan to stop working, common reasons why your radiator fan is not turning on, problem might be with the radiator itself, Coolant In Oil – Can Cause Catastrophic Problems, Why a Car Stalls While Driving And What To Do When It Happens, Avoid These 10 Bad Driving Habits That Could Ruin Your Engine. If you are satisfied that the thermostat settings are correct, check your … The first thing I did after the temperature sensor did not work was go to Pep Boys and sequentially go through the relays. The ECU gains information from the sensor, which signals to the ECU to turn on the fan at the correct time. The job of the radiator 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. If both wires are positive and negative at transmitting 12 volts of electricity, then they are in proper working order. Later, I tested the cooling relays one and two. If the belt/viscous clutch fan is moving enough air (assuming your car has auto transmission), electric fan won't run. A radiator fan is imperative in keeping the temperature of the coolant low enough. Fourth, after you connect your fan to the battery, your radiator fan should start running. If the fan comes on when the air conditioning is operating at maximum volume, but doesn’t run properly when the engine is warm or hot, then you might need to check the temperature switch. 3. For this test, the only tool that you need is a test light. Almost seems like it has got to be crud inside the radiator where this normally closed COOLING FAN SWITCH screws into and is not opening the switch circuit when the coolant reaches the correct tempture. Depending on if and when the radiator fan comes on will affect what you should do next, and if the radiator fan has stopped working. I repaced the coooling sensor twice and both were no good, so I went to a diferent store to try another one. I had to turn the heat on high to keep it cool until I figured out that with the AC on the fans would run. Connect one lead to the power circuit and one lead to the power terminal. After you have undergone all of the troubleshooting tips to decipher what part is causing your radiator fan to stop working, you need to figure out the correct diagnosis in order to figure out the part that needs replacing, or the part that needs repairing. This article pertains to all vehicles. 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