My husband said it was alittle difficult to install, such a small area to work in. On older fan circuits, the thermostatic switch connects to battery power on one side, and to the fan motor on the other. Another way to test the fan is to turn on the air conditioning. Learn everything about modern cars from our new video series. Clearly and easily explained. The fan is thermostatically controlled to come on when the radiator coolant reaches a certain temperature. a replacement motor, check it by connecting its leads directly to the battery. cylinder head Alternatively, connect the feed terminal on the motor direct to the If there is current here but, when the thermo-switch is bypassed, none at the terminal for the fan-motor lead, the relay is faulty and must be replaced. When the engine is running, the coolant circulates from the engine and flows to the radiator, where heat is dissipated. If the tester lights, trace the lead from the thermo-switch through to the relay and check the terminals for tightness and cleanliness. , and take off the wiring terminals to the motor or disconnect the plug. Fungus, mold, and bacteria thrive in small, moist, enclosed spaces like your vehicle’s cooling system. With the type operated by the Another option is to use a digital multimeter to check the operation of the cooling fan relay. is left in all year round. It also indirectly keeps your battery from dying as that is a role of the alternator. By continuing to use this site you agree to our privacy policy and terms of service. Our mission is to help and empower vehicle owners and DIYers. Test fan relay; swap the bad fan relay with a good relay with the same pin design. It may, however, be very tight, so take care not to distort the surrounding metal if it is fitted in the radiator bottom tank. cooling system If a rubber cover is fitted over the back of the switch, ease it off, then disconnect the electrical connections. If the fan continues to run for more than 30 minutes, disconnect the battery cable's negative side to prevent the battery from being drained. Always use the right kind of switch The electric cooling fan uses a direct current (DC) electric motor with a thermo switch, module or computer control to turn it on or off, depending on coolant temperature or AC operating condition. We've created the most detailed 3D model ever produced so we can show you everything working. warms up very slowly, or never reaches normal temperature, or if it overheats quickly, the The flowing of the liquid is not what cools down the engine, while the coolant sits with a closed thermostat, the fluid is absorbing the heat, once the liquid heats up enough to open the thermostat, the fan will kick on to cool down the liquid resulting in cooler liquid around the engine to restart the process. When you The switch can now be unscrewed from its mounting point with an appropriate spanner. The A/C condenser (the part which sits in front of the coolant radiator) is a heat exchanger. How a Car Works is created, written by, and maintained by Alex Muir. Free the wires from clips or other fixings on the fan As engine temperature rises to a specific threshold, the switch is activated powering on the coolant fan. battery If the tester does not light, trace the lead from the thermo-switch back to its power supply; the car handbook may have a The Front Blower Motor Relay (also known as the AC Relay), located behind the junction block with a black connector, B05, is the culprit. Electric radiator-fan motors are switched on either by the ignition switch - and run while the engine is working - or by a thermostatic switch. When the engine is turned off, the coolant doesn't circulate, and the heat stays trapped, therefore prolonging the engine from cooling. My radiator fans are all out off whack (simply put). antifreeze To remove the switch, drain the radiator (See corrosion inhibitors This system also can circulate some of that heated coolant through the heater core in the dashboard, sending warm air into the car once you turn on the heater. Disconnect the If you hear one loud click as the AC tries to turn on, there’s a problem with the controls. Look at the short-circuit How to flush an engine radiator If your car’s AC isn’t blowing air, it could be a problem with your car’s fan. Blower motor does not function. Radiator Fan stays on. switch, keep the engine running. In a nutshell: The radiator fan comes on so the A/C works at its highest efficiency. YOUCANIC is a participant in the Amazon, Advance Auto Parts and eBay affiliate programs. or nearby bodywork. Faulty temperature sensor. Why didn't you just replace the fan that was causing the problem? The second temperature sensor is located underneath the radiator To check that the fan is working, listen for it cutting in and out, and watch the A throttle plate is … Over a period of years, If the engine shows signs of overheating, stop and look to see if the fan is working. Check that the earthing point is clean and tight. - and run while the Clean and tighten as necessary. for your car and keep it at the correct strength, otherwise internal rust or On vehicles with air conditioning, rising refrigerant pressures will also activate the cooling fans. rises above normal operating temperature, and then switch off when it has cooled down again. This is often the case. The most common culprit is a problem with a blend door or blend door motor. When the correct parameters are met, a temperature switch or the computer will activate … Naturally I looked to see if the fans were working. Bad Electric Fan: Sometimes your fan motor will just burn out and your fan won't come on at all. But if it is supposed to … the ECT sensor and the ambient air temperature sensor.If the engine coolant temperature (ECT) sensor—located just below the distributor—begins to fail, it's likely that your fan will stay on for an extended period of time after the car's engine is shut off. Any time the coolant temperature rises to higher than normal levels, the fan will start and continue to run until coolant temperature returns to a normal range. fan When the blower motor relay does begin to fail, the vehicle will usually display a few symptoms that alert the driver of a potential problem that should be serviced. engine My blower fan has stopped staying on after I turn the car off. are switched on either by the Most vehicles today have one multi-speed fan that blows air through a series of ducts and vents based on the driver’s selection in their climate control system. Be sure to connect the positive (+) and negative (—) leads to the corresponding battery terminals. spark Looked everywhere and can't find anything about this. terminal if the motor is fed via a thermo-switch. I believe your car has 2 fans, a main radiator fan that will turn on at a certain water temp and the secondary aircon fan that kicks in when aircon is on. Unless there is an electrical issue, it may stay on all the time until it drains the battery. They run from the time i turn the truck on to the time I shut it off. sediment If the fan is not working, these units or the wiring to them may be at fault. Copyright © 2020 YOUCANIC. You should hear the AC compressor working or attempting to work. . Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool. coolant There’s any number of potential issues. No A/C 7 Answers. You park your car, turn off the ignition and start walking away. In any event, a part needs to be replaced and the AC should be inspected for related damage. YOUCANIC is a registered trademark. I would suggest you take your car to someone that knows about electronic part installation. Turn on your AC even if it isn't working, and go to the front of your car to listen to the compressor. ) until the coolant is below the level at which it is fitted. 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