Both fans run continuously. But if you stop, for example in a traffic jam, your engine has to use an electric cooling fan to force air through the radiator. Cooling Fan Relays and Fuses. The mechanic will check to see if all the wires to the fan are properly … 3. Start by looking for the blower fan resistor. Electronic types might freewheel, but most fan clutches should spin with a little effort. Comment; Flag ; More. I pulled out them each and realized that they are both identical and by looking at them I could tell that the one pictured below was likely bad because of the discoloration, which is most likely from over heating: A failed module may also prevent one or both fans from operating, or the compressor clutch from engaging. A 4 terminal relay is used so a low power circuit may engage a high power circuit without risk of damage to the low power control circuit. The two fan fuses (30A and 40A) are in the same location. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on. The most obvious sign that your start relay isn't working is the lack of cooling caused when the compressor never starts up. Replace the relay. One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. Chrysler minivans (late 1980s and early 1990s). The cooling fan motors work together with the cooling fan blades … The controller is supposed to switch on both fans when the compressor clutch is engaged. The module is mounted on the radiator shroud and is exposed to a lot of heat so failures are common. You'll also see one or all of the following symptoms as the engine overheats: The electric radiator fan motor does not come on. The relay is the component that fails most often, so be sure to test the relay as well as its power supply and ground connections. If the cooling fan motors burn out or fail, the cooling fans will be disabled. The Low and High fan control circuits are separate from the ICE module all the way to the fan motor. If the 2 lines are depicted as meeting at the circle or dot, the relay is a normally closed (NC) relay. How to Tell If Your Home Thermostat Is Bad. The quickest way to tell whether or not the electric fan(s) are working is to start the engine, let it reach normal operating temperature and then turn the A/C on. Check the power. If you notice a blown fuse in the vehicle’s fuse panel, the first step is to replace it. The only tool required to check a relay is a multimeter. If there’s an issue with the relay, the fan will be affected. Normally open are the most common type. Symptoms Of A Bad PWM Fan Relay. I know nothing of these things. If the fans aren't supposed to come on when the CTS is unplugged, maybe just the sensor that tells the fans to come on when AC is turned on is bad....whatever sensor that is. The problem is the two fan motors pull so much amperage that they rob voltage from the clutch. Some folks will tell you that a bad cooling fan relay can also cause this. If You Think The Problem Is The Cooling Fan Relay, Test It ! The most common symptom of a faulty cooling fan motor are cooling fans that do not come on. If you notice that your engine is running at higher temperatures than normal, that may be a sign that the relay is not functioning properly. The 200+ Best, Hidden & Most Powerful Features & Changes for iPhone, 22 Things You Need to Know About iOS 14's Newly Redesigned Widgets for iPhone, Best New iOS 14 Home Screen Widgets & The Apps You Need, 13 Exciting New Features in Apple Photos for iOS 14, 9 Ways iOS 14 Improves Siri on Your iPhone, 16 New Apple Maps Features for iPhone in iOS 14, 19 Hidden New Features in iOS 14's Accessibility Menu, Every New Feature iOS 14 Brings to the Home App on Your iPhone. I assumed a blend door was bad, but noticed the electric cooling fans were not coming on. Defective fan relay. It is important to know if the relay is NO or NC during further testing. The quickest way to tell whether or not the electric fan(s) are working is to start the engine; let it reach normal operating temperature and then turn the A/C on. These use a solid state relay for the cooling fans, and the relays tend to overheat and fail. Electronic types might freewheel, but most fan clutches should spin with a little effort. The engine control module provides ground to the fan relays when cooling is needed, and a dropping resistor is located inside each fan motor for two-speed operation (that’s why each motor has two power input terminals but only one ground terminal). Please I am not trying to sound like a smart ass. The plug that goes into it has 3 wires (this is the plug on the left side when standing in front of the car facing the fan, the device mounted to the top of the fan is an air particle sensor and has no bearing on the cooling system). The quickest way to tell whether or not the electric fan(s) are working is to start the engine, let it reach normal operating temperature and then turn the A/C on. In either case, if your compressor makes a clunking, creaking, mechanical noise, this is a bad sign. Locate the circuit breaker and ensure it hasn’t tripped. In general there are six things that may prevent an electric cooling fan from coming on; Defective temperature switch; coolant sensor or other sensor; Engine thermostat is stuck OPEN (engine never gets hot enough to turn on the fan) Faulty fan relay; A wiring problem (blown fuse, loose or corroded connector, shorts, opens, etc.) Step 1 - To test for intermitted relay failures which are common, remove the relay in question, take a small wire strand, about two inches long and insert it into the relay connector terminal 87 or 30. Then it's a problem with the heat censor. One symptom here of a failed module is a car that cranks but won’t start because the fuel pump isn’t getting any power through its relay. If necessary, a replacement relay costs around $20. If your fan relay does not have markings on it, you will have to consult the cooling fan wiring diagram found in your vehicle service manual. If the relay shorts or fails, it will not be able to supply the power for the fans to operate and keep the engine running at normal … Your email address will not be published. If the cooling fan motors burn out or fail, the cooling fans will be disabled. Shake the relay in your hand and listen for a rattle. Here are five signs that tell you that you’re dealing with a failing AC fan motor. Dual relay. Use a voltmeter to measure voltage to the clutch. Ford cooling fan controllers (late 1980s and early 1990s Mustangs and other models). If it fails to cool down after several minutes, or seems to be emitting unusually warm air, there could be a problem. Look for obvious signs of corrosion and burns from overheating. Save my name, email, and website in this browser for the next time I comment. Symptoms Of A Bad Radiator Fan Relay. The only tool required to check a relay is a multimeter. Answer . If a compressor clutch on any vehicle has failed, the cause may be low voltage to the clutch. Disconnect electrical connector for the thermofan switch. Turn the ignition to the "ON" position and jump terminals 87 and 30 the relay is now jumped and the accessory should activate, if so the relay has failed. The relay is hot because it's being "switched" on and electricity is running through it but it's not being drawing by the fan motor. MyMoto Nigeria. The fan won’t start even though the AC is on. Once this happens, your air conditioning unit is at … Somethings not right - you can hear the compressor start to growl at idle, pull the idle down, then cycle off. Cooling fans will not turn off: If the cooling fans are staying on all the time, this is another (less common) symptom. I pulled out them each and realized that they are both identical and by looking at them I could tell that the one pictured below was likely bad because of the discoloration, which is most likely from over heating: Outside AC unit turns on now that I replaced the thermostat, but no fan. They are hooked to the 50 AMP fuse in the glove box #36. One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. There are three ways to check for a bad terminal. If the test above fails to activate the Radiator Cooling fan, then the 30 amp Cooling Fan fuse in the Main Relay and Fuse Box is blown, or the Cooling Fan Relay or Main Relay has failed open, or the fan motor is bad. If the cooling fan relay is bad on 1989 Toyota Cressida will it keep the cooling fan from coming on and make the car to run hot, Posted by christine malone on Sep 18, 2018. The cure may be to require the clutch circuit by adding a new relay so the clutch can have its own dedicated power circuit. well i did cooling system overhaul and replaced lot of parts but some how electric cooling fan dont come on when engine is normal or high temp? Clicking this will make more experts see the question and we will remind you when it gets answered. When you ground this wire, you should hear the relay click and the fan(s) should come on. Now, this is where things will get a little goofy. Shake the relay in your hand and listen for a rattle. The quickest way to tell whether or not the electric fan(s) are working is to start the engine, let it reach normal operating temper ature and then turn the A/C on. Went out of town and left my fan on for 5 days straight by accident. Check the Fan. The typical electric cooling fan circuit includes a temperature sensor, a relay, a control module and the fan motor. See how to use continuity checks to identify the problem and make sure that the fan motor, electronic control board and the wiring that connects them are work correctly. Open up the frunk and watch for the cooling fans to come on (this is assuming of course you have already removed the frunk plastics). You'll also see one (or more) of the following symptoms: Your temperature gauge will max out (as you're driving around). The GTO, and I assume that this is because it is made in Australia, uses non-standard relays. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser. Your email address will not be published. If the fuse is intact, ensure the switch is … How do you know if your fan relay or motor is bad? Hook the fan directly to car battery, if it works, try to hook the fan just before the relay, and if it works, test the relay by connecting a 12v current to the relay (to the connector that makes the relay conduct current, usually there is a diagram under the relay) if the fan spins while in place, the relay is good. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser. If it is not within 0.2 volts of battery voltage, other components in the circuit may be stealing power from the clutch. Bad temp. How can you tell if a cooling fan switch is bad on a 1996 Pontiac sunfire? (This test will not activate the A/C Condenser Fan.) The armature closes when the coil is energized to route power to the fan motor. The cooling fan Low (20-amp) and High (30-amp) relays are located in the engine compartment relay tray, and labeled on the lid of the box. Low voltage allows the clutch to slip, which creates excessive friction and heat. Look for obvious signs of corrosion and burns from overheating. The most obvious sign that your start relay isn't working is the lack of cooling caused when the compressor never starts up. The cure here is to add a separate relay for the compressor clutch so the clutch can draw full voltage from the battery. Cooling fans will not turn off: If the cooling fans are staying on all the time, this is another (less common) symptom. Be the first to answer! The easiest way to determine if the relay contacts are stuck is to tap the relay with the handle of a screwdriver. If this sound never happens and the temperature inside the fresh food compartment and the freezer begins to rise, then there is a good chance the start relay isn't functioning properly. When the fan doesn’t start even though the AC is turned on, it can be a clear sign that there’s a fault with the motor. sensor? If this sound never happens and the temperature inside the fresh food compartment and the freezer begins to rise, then there is a good chance the start relay isn't functioning properly. Step 1. It may cause the fan to cut in and out, or not come on at all. Look at the markings on top or side of the relay case and locate the two control circuit terminals, which connect to the relay's coil, and the two power circuit terminals, which let electrical current pass to the fan. Some vehicles will have a high-speed relay and a low-speed relay. Im just telling what I read. How does a car’s cooling fan work? There are, … If the cooling fan motors burn out or fail, the cooling fans … Step 1 – Check the fan switch relay. In many cases, the underlying fault is a bad cooling fan relay. If no power is observed at either 87 or 30, the fusible link or maxi fuse has shorted. There are several ways to tell if a bad cooling fan relay is to blame for an overheated engine. The IRCM module also provides two-speed (high and low) fan operation by using an internal resistor to drop voltage to the fans. Switch on the A/C and turn it down to the coldest setting. The thermostat controls both the heating and cooling systems of homes with central heat and air conditioning, or just the furnace in homes without air. If the fan doesn’t spin at all, the bearing may be seized. When the fan doesn’t start even though the AC is turned on, it can be a clear sign that there’s a fault with the motor. If the power is fine, check to see if there is proper voltage. To test the fan motor on your air conditioner, you’ll have to do a continuity test. Then it's a problem with the heat censor. I wired the fans directly to the battery and they work. Click here for a video tutorial. Usually a bad or failing cooling fan motor will display a few symptoms that can alert the driver of a potential problem that should be serviced. If it does not rattle, the relay is good and the compressor is bad and will need to be replaced. It's probably a bad cooling fan motor and you need to get a new one. Another simple relay test is to shake it. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on. Engine overheating or poor air conditioning performance can be caused by an engine or A/C condenser cooling fan that fails to come on. Why? Testing. When you're driving, air flows through the car radiator to keep your engine a normal temperature. If it does not rattle, the relay is good and the compressor is bad and will need to be replaced. on most ford contour cars the cooling fan only runs when the motor reaches a certain temp. If the cooling fan motors burn out or fail, the cooling fans … Look for the location of your relay in your owner's manual or in the fuse panel inside the car or under the hood. If they don’t come on after 5 minutes or so or just one comes on it means you have a problem somewhere. A repair manual can tell you where its location is in your vehicle’s make and model. Try moving the fan forward and backward. Mymoto Nigeria: meeting your automotive needs. Your Honda Civic … The quickest way to tell whether or not the electric fan(s) are working is to start the engine; let it reach normal operating temperature and then turn the A/C on. Just trying to stop my fan from running all the time. If resistance is high, the coil may still be working but it is failing, or it may not work when electrical loads are high. Cooling Fan Relay Diagnosis Now for the relay, or relays. Temperature gauge on the instrument cluster is maxing out. The armature is normally closed and is pulled open when energized. Both fans should come on when the A/C is on. Inspect the resistor visually. Ford integrated relay control module (IRCM) (introduced in 1986). Example: Testing the radiator cooling fan relay, the cooling fan should be operating. Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. How to Test Cooling Fan Relays - Low and High Speed - YouTube If the fan spins more than three times, you may have a bad fan clutch. :cry: They should both come on in just a few minutes on a warm day. If it rattles, the relay is bad and can be replaced by going to an appliance store and getting a new one. Inspect the resistor visually. Designed by Webspace NG, Diagnose Engine Cooling Fan Relay Problem, 5 Car Transmission Problems You Should Never Ignore. The engine may also run hot and overheat, too. Coolant bubbling out of the coolant reservoir. Switch on the A/C and turn it down to the coldest setting. On many vehicles, there may be two fans: a main cooling fan for the radiator, and a second fan for the condenser. The two large wires are for power and ground, they are always live even when the car is off. If one of your accessories doesn't come on and you suspect the relay is bad, you can perform a few simple tests. If … I did a search for this and read the aux fan is only for the A C. Someone said the clutch fan is sufficient for engine cooling and there was no need for an Aux fan, this was only for AC condensor. A normal relay’s internal wiring will go from “87”, “85”, “30” & “86”, in a clockwise pattern starting at the top. The controller contains a fan primary relay, A/C fan control relay, and wide open throttle cutout all built into one unit. A repair manual can tell you where its location is in your vehicle’s make and model. The filter is mounted in a hot area and tends to fail, preventing the cooling fan from operating. They sell generic cooling fans at any good parts store that you can mount to your radiator. Comment; Flag ; More. Cooling fans do not come on. If the coil has no resistance, it is open and has failed. In many cases, the underlying fault is a bad cooling fan relay. On this vehicle, you should use a scan tool to see which of these inputs is energizing the fans and when. However, with the ignition off, the thermofan switch and relay would both have to fail to cause the problem. How to Tell if Cooling Fan Relay is Bad. This unit controls the both fan relays, compressor clutch relay and the fuel pump relay. how can i tell its not burned up or how can i test this problem? Spin the fan. 1. You can usually hear the intermittent humming of the compressor throughout the day. On most Chrysler vehicles, the cooling fan relay must be engaged before power can go to the A/C clutch. Email: support@mymoto.com.ng, © 2017. Adverts/Inquiries: What goes bad on a relay? 1 - Radiator Cooling Fan Relays. Faulty wiring could be to blame. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser. Jump-start your career with our Premium A-to-Z Microsoft Excel Training Bundle from the new Gadget Hacks Shop and get lifetime access to more than 40 hours of Basic to Advanced instruction on functions, formula, tools, and more. Coolant bubbling out of the coolant reservoir. The cooling fan in the engine compartment should turn on to pull air through the … Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. Hook the fan directly to car battery, if it works, try to hook the fan just before the relay, and if it works, test the relay by connecting a 12v current to the relay (to the connector that makes the relay conduct current, usually there is a diagram under the relay) if the fan spins while in place, the relay is good. Hold your hand a few inches away from the vent so slight variations in temperature will be more noticeable. sensor? If You Think The Problem Is The Cooling Fan Relay, Test It ! All Rights Reserved. The most obvious symptom of a bad PWM fan relay is that your Jeep is gonna' overheat. If it rattles, the relay is bad and can be replaced by going to an appliance store and getting a new one. Relay contact can pit and stick closed, causing a motor to run constantly. After locating the fan relays (the GTO has 3), you’ll want to pop the main relay off and jump it. Before you start, make sure the thermostat is set to cool and that the temperature setting is as low as it will go. Chrysler LH cars (since early 1990s). If your refrigerator isn't cooling and you don't hear the fridge fan running, this video guides you through diagnosing what's wrong with the refrigerator evaporator fan. I think they’re supposed to be on when the AC’s running. The cooling fans on Chrysler cars are not particularly well-made, but that doesn't mean you can assume that they are broken the second the cooling system stops working. Want Answer 1. In many cases, the underlying fault is a bad cooling fan relay. Cooling fans do not come on. Check the electric resistance of each of the resistor’s terminals with a multimeter. If any of the subsystems inside the IRCM module have failed, the whole module must be replaced. Three fuses in the power distribution box protect these circuits. If fan stops, the thermofan switch is most likely bad. Your fridge also contains a condenser fan typically situated next to the compressor unit. Here’s how to tell if your cooling fan isn’t working, what you should do about it and what the problem might be. If one or both fans fail to come on, the lack of additional cooling provided by the fan may cause poor A/C cooling performance, and it may cause the A/C compressor to overheat and fail. Hold your hand a few inches away from the vent so slight variations in temperature will be more noticeable. Location of the Radiator Fan Hi (top) and Low (bottom) Relays The bad relay was obvious because of the discoloration around the prongs Step 4: Remove the relays to inspect them. If the fan relay has failed, it will prevent the compressor clutch from engaging and there will be no cooling. Sometimes, when the electric motor begins to wear out, has failed or has issues with bad wiring, the fuse that controls the fan relay will blow out. Wiggle the fan. At 238 degrees F, the fan relay switches power from the low-speed circuit to the high-speed circuit to increase cooling. The fan relay controls the power to the cooling fan. The radiator fan switch relay may not be supplying power to the fan. Consequently, the compressor clutch may only get 9.8 volts instead of full battery voltage causing it to slip, overheat and fail. 1. If it wobbles more than a quarter-inch or you feel it clicking, this may indicate a worn bearing. It is getting power but will not turn on. The cooling fan in the engine compartment should turn on to … Premium A-to-Z Microsoft Excel Training Bundle, What's New in iOS 14? Noisy Fan 1. The vibration usually causes the contacts to open. You can do this at the transformer, checking for a fuse in the low-voltage circuit. If there isn’t, check to see if the appropriate fuse has blown. 1. Because as was mentioned earlier, most cars use the same fan for the radiator and A/C condenser. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on. Step 1 Open the hood and/or fuse compartment so … The easiest method is to start the engine and then turn on the air conditioning. Normally closed. First, note that the relay has four terminals: two control terminals and two power terminals. Want Answer 1. I unplugged the engine coolant temp sensor and the fans still did not come on. Other inputs that can affect when the fan relays are energized include engine temperature, transmission temperature, intake air temperature and A/C operating pressure. Who doesn't love being #1? The cooling fans on Chrysler cars are not particularly well-made, but that doesn't mean you can assume that they are broken the second the cooling system stops working. A bad fan motor If it’s not working, the fan won’t turn on when it needs to, which means the engine might overheat. See the Tips section at the bottom for more information. 1 2. I believe they’re supposed to default to “on” if there’s not signal from the coolant temp sensor. This is a good test to determine that the relay and fan motor are working. (Ignition ON) Bad thermofan switch. With the relay removed from the fuse box, the multimeter set to measure DC voltage and the switch in the cab activated, first check to see if there are 12 volts at the 85 position in the fuse box where the relay plugs in (or wherever the relay is located). If it fails to cool down after several minutes, or seems to be emitting unusually warm air, there could be a problem. Since the radiator fan motor relay is one of the main components that gets your Honda Civic's radiator fan motor to run.. when it fails the most obvious symptoms that your Honda Civic will experience is overheating. If the 2 lines are depicted as not connecting at the circle or dot, the relay is a normally open (NO) relay. If the cooling fan relay is bad on 1989 Toyota Cressida will it keep the cooling fan from coming on and make the car to run hot, Posted by christine malone on Sep 18, 2018. Step 2 - Next, reinstall the relay while keeping the wire strand inserted and clear of any other terminals or metal (ground). The thermostat controls both the heating and cooling systems of homes with central heat and air conditioning, or just the furnace in homes without air. The fan won’t start even though the AC is on.