Consequently, Some vehicles have as many as three; One for a dashboard warning light If The Fuse Is OK Move On To The Next Step. The radiator fan switch relay may not be supplying power to the fan. Set the … Bypassing The Radiator Fan Relay. Normal voltage for a radiator fan is around 12 volts. I just replaced my fan switch with the Neuspeed 3 pole switch that brings the fans on at 80 degrees. Connect one of the ohmmeter probes to one of the thermostat terminals and connect the other probe to the second thermostat terminal. If you're rusty or new to this automotive element, here's a short rundown of how radiator fans work. Clicking this will make more experts see the question and we will remind you when it gets answered. The old 4 wire motors have quite a short life and fail between 60 - 80k miles. Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. ). If the fan motor now works, the switch is faulty. See the Tips section at the bottom for more information. Step 5. HOW TO TEST RADIATOR FAN SPEEDS FROM TRINARY SWITCH (DIESEL CDT/i, 1.8 & KV6 Variants. Connect one end of the volt meter to a ground and the other end to the electrical connection on the fan. Older cars have glass; cylinder-shaped fuses with stainless steel on the ends and glass in the middle. If your fans are not running when they should (or are running when they shouldn't), these steps will help locate the problem. The temperature switch on most vehicles is typically connected to your car computer, or your powertrain computer. Step 2. Be sure you have the right one. At times, your cooling fan stops working because a sensor has gone bad, but the fan works just fine. He also currently owns and operates Sophisticated Curves, an online fashion mall that caters to the needs of plus size women. Connect one end of the 12-gauge jumper wire to the black ground wire of the fan. It may cause the fan to cut in and out, or not come on at all. This switch is configured to work based upon the temperature of the engine. In conclusion. Comment; Flag; More. When the water reaches between 180 to 220 degrees Fahrenheit, the switch should turn on and the resistance seen by the ohmmeter should change to zero. The drawback to water-cooled systems is that the thermostat, thermostat fan switch and the fan itself must all work together to keep the system from overheating. The fan should 'ramp-up' from 0 to 100% and back to 0% speed. If it does not, check to see that there is current flowing to the switch by using a … If the fan does not operate check the Measuring Value Block ( MVB) Group 135, field 2 will show you in (%) the current fan output speed from the ECM. The ohmeter should be turned on and have a reading of high resistance. Use the volt meter to test if there is power to the wires. Place the thermostat switch in the sauce with the terminals turned up. You just need to know the correct steps. So, If you find a blown fuse replace it. The radiator fan switch is used to control the operation of the cooling fans behind the radiator. Since the fan motor isn't activating on its own... the next step is to check the radiator fan motor switch. STANDARD RELAY PINS 30: Constant 12V, unswitched 85: Signal (switched … The fan relay controls the power to the cooling fan. The thermostat switch can be tested easily after it has been removed from the vehicle. The best way to test it is to bypass the fan's normal circuit and straight wire the fan to the engine. The volt meter will then give you a voltage reading. Using a multimeter is another good way. We do not intend to infringe any legitimate intellectual right, artistic rights or copyright. When the water reaches between 180 to 220 degrees Fahrenheit, the switch should turn on and the resistance seen by the ohmmeter should change to zero. The fan will then cycle on and off as needed to maintain the proper coolant temperature. This is the detailed process of how to diagnose an overheating problem (Radiator Fan not working) on a 1997 Honda Civic. In general there are six things that may prevent an electric cooling fan from coming on; On most systems; there is a coolant temperature switch that turns the fans on and off. When it reaches that temperature; the switch closes and turns the fan(s) on. So in order to how to check if radiator fan is working, you have to check the voltage of a few fuses in the under-dash fuse box (number 3, 15, and 20) and under-hood fuse box (number 47 and 50). 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. 1 Answer. After several requests from members, thought I'd put it here for reference. If the fan clutch requires repair, take the vehicle to a qualified mechanic. TEST 1: Checking The Radiator Fan Relay Power Circuits. If it doesn’t, and you have a domestic vehicle; the coolant temperature switch is a normally open type that stays open until the coolant reaches its set temperature. If it spins more than three full rotations, this indicates that it may be prone to slipping. Test the third set of wires: With the negative black multimeter test lead still on the brown wire, take the red test lead and take it off of the white wire. TEST 2: Bypassing The Radiator Fan Relay. The switch is essentially a thermostat that senses the temperature of the coolant. Your engine cooling fan will not work if you have a blown fuse. In this test step, we're gonna' test all of the circuits of the fan relay by bypassing the radiator fan switch with a jumper wire. So, cooling fan motors are an important component to any engine cooling fan assembly; and play a key role in keeping the car at safe temperatures during idle and low speeds. Locate the coolant temperature switch and unplug it. Replace it and you are back on the road. Turn on the burner and slowly increase the water temperature. Turn on the burner and slowly increase the water temperature. The tip of the (ECT) sensor protrudes into one of the cooling system passages; and […], Today the radiator cap, is more important than ever before. The first step is checking for a blown fuse. TEST 2: Bypassing The Radiator Fan Relay. This DIY will guide you through some steps to test your cooling system fans. You should read infinite resistance. To check this, unplug the single wire connector and, using a jumper wire, ground it. Be sure you have the right one. The switch is located about 2/3 of the way down the end of the radiator. The process of wiring this switch is relatively easy. TEST 2: Bypassing The Radiator Fan Motor Switch. After confirming that the radiator fan relay is getting juice (TEST 1), the next step is to jumper circuits 1 and 2 with a jumper wire to see if the radiator fan motor comes on. Protects relay from arcing damage due to fan spinning after shut-off. How do you test the radiator fan relay switch on a 1999 plymouth voyager. Basically all you have to do is spin the fan blades and see how long they keep spinning. The switch has 92C/87C stamped on it so I assume it is supposed to turn on at 92C and off at 87C. First, you need to connect your test light to the battery ground. For more information about how to test a fan clutch, such as other signs to look for which indicate damage, read on. For this test, the only tool that you need is a test light. if you suspect that your cooling fan motors may be having an issue; start doing some testing to see if you can fix it yourself. Print this page; Share this page × Ad. A fan failure; or a failure of the fan relay or control circuit is bad news; because it can allow the engine to overheat. So, The fan runs mostly at idle or low speed when the engine is at normal temperature. Another easy test is to see if the motors work. Step 1. Level 3: An expert who has achieved level 3 by getting 1000 points. Electric radiator fans operate when radiator temperature rises to preset heat range. Copyright 2020 Leaf Group Ltd. / Leaf Group Media. Fortunately, nine out of 10 times, engine coolant leaks are easy […]. That may be all you need to get back on the road. He currently holds a Bachelor of Science in electrical engineering from the University of North Carolina at Charlotte and a Master of Business Administration from the University of Phoenix. Most Japanese cars have a normally closed switch. Extra cooling is not needed when a cold engine is first started; so the engine cooling fan does not come on until the engine reaches normal operating temperature. I am getting ready to put my re-cored radiator in the car and decided to check the thermal radiator fan switch before reinstalling it. On most systems; there is a coolant temperature switch that turns the fans on and off. Hydrolocked Engine – What Is It – What Damage Can It Do, Engine Coolant Temperature (ECT) Sensor – Function – Failure And Testing, The (ECT) sensor, is an engine management system sensor; that is used to monitor the temperature of the engine’s coolant. Step 4. Battery out including the box, intercooler pipe off, map sensor disconnected, wiring moved and a deep 30mm socket from Halfords to loosen the switch. I put it in a pot of water and monitored temperature and resistance as the water heated. If the fan motor is not at fault, leave the ignition switched on, take the connections off the thermo-switch and briefly touch them together. Locate the coolant temperature switch and unplug it. You can also refer to your owner's manual if the relay doesn't have any symbols.Resistance Test: 1. The first components that should be tested are the cooling fan, the cooling fan relay and the thermostat switch, which turns the fan on and off depending on the temperature of the engine. When the radiator temperature lowers to a preset level, the electric fan turns off. Place a small sauce pan on the stove and fill it with one cup of water. For this test, go to: TEST 2: Bypassing The Radiator Fan Motor Switch. Consequently, if it does not spin it is blown. Defective fan control module; The Next Thing To Test Is The Coolant Switch Or Sensor. The ohmeter should be turned on and have a reading of high resistance. If one spins a lot shorter ammount of time it could mean it’s either dead or on it’s way out. If the volt meter reads 12 volts, the problem is not the power and the fan needs to be replaced. The radiator fan should spin. Place the thermometer in the sauce pan so you can read it as the temperature increases. This is a DIY test with No T4 TESTBOOK required !! You will now place the red probe on the common wire. The fan may work but it only runs at low speed; which may not be fast enough to prevent overheating. COPYRIGHT © 2020 DANNYSENGINEPORTAL.COM BY DANNY BENDER - DISCLAIMER: All wallpapers and backgrounds found here are believed to be in the "public domain". NOTE: You can modify the above tests to suit your particular diagnostic needs. If you are the rightful owner of any of the pictures/wallpapers posted here, and you do not want it to be displayed or if you require a suitable credit, then please contact us and we will immediately do whatever is needed either for the image to be removed or provide credit where it is due. Bypassing the radiator fan switch. Cut both wires and strip 1/2 an inch of insulation off of the ends of the two fan wires. The cooling fans should turn on when the sensor in the bottom passenger side of the radiator detects that the coolant temperature has exceeded 172°F, or when the air conditioner is turned on. Stephen . William Kinsey lives in Concord, N.C. Unplug the Fan Connector closest to the fan. The Next Thing To Test Is The Coolant Switch Or Sensor, (ECT) Engine Coolant Temperature Sensor – What Can Go Wrong, Radiator Cap – Basic Function – Failure Symptoms – How Important Is It, Engine Coolant Leaks – How To Find Them – How Bad Are They, Timing Belts – Why Should You Replace Your Engine Timing Belt, Engine Spark Knock – That Annoying Knocking, Pinging Or Rattling Sound, Tailpipe Smoke – What Does The Color Of The Tailpipe Smoke Mean, Valve Lifters – Hydraulic And Mechanical – What Is The Difference, Engine Bearing Replacement – Learn How To Replace Engine Bearings, PCV Valve System (PCV) (Positive Crankcase Ventilation System), Radiator – Overheating, Causes, Consequences And Maintenance, Spark Plug Problems – Troubleshooting, Failure Symptoms, Replacement, Vacuum Leak Repair Locations – Common Causes – Common Repairs, Engine Coolant Temperature Sensor (ECT) Replacement – How To Do It, Defective temperature switch; coolant sensor or other sensor, Engine thermostat is stuck OPEN (engine never gets hot enough to turn on the fan), A wiring problem (blown fuse, loose or corroded connector, shorts, opens, etc. Defective fan relay. 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. It was a git of a job. Connect the leads of an ohmmeter to the power terminals on the relay. This switch works by eliminating the ground connection when it is switched "off" and reconnecting the ground when it is "on". Test The Radiator Fan Temperature Switch . Step 2. If the resistance does not change to zero, then the switch is bad. If necessary, a replacement relay costs around $20.There are three ways to check for a bad terminal. He also has several years experience as an outside plant engineer and planner with AT&T. I want to make it clear this test isn’t going to give you a definitive answer but it can help to point you in the right direction. Faulty wiring could be to blame. Bypassing The Radiator Fan Switch. The easiest way to check it is; visually check it for a continuous wire with no breaks. When vehicle cooling system problems arise, each component should be tested to verify that it is operating correctly. Locate the positive and negative wires on the cooling fan. A way to get around this situation is to wire in an on and off switch. Adding a manual switch to an electric radiator fan is an economical way of keeping your car cool and in good condition. Make up some jumper cables; connect them directly from the battery to the fan motor to see if it spins. MVB -137 will show you some AC system status/request info. If It Is Working; Move On To The Next Step. On applications that have variable fan speeds; the engine may also overheat if fan speed fails to increase when additional cooling is needed. Refer to the top or side of the relay to locate these terminals. Testing LOW SPEED FAN This test is straight forward and is done with one press of a button! Yours could be blown so you will need to check it. Kick off the engine or switch the ignition key off to IG2. ADJUSTABLE FAN SWITCH WITH RADIATOR PROBE (GROUND SWITCHING, NON-VARIABLE SPEED ONLY) 30-40 AMP FAN 1 FAN 2 HAYDEN 3653 PN: IN5408 Make sure the diode band is facing toward the fan or relay and away from ground. At this point the fan should come on. After confirming that the radiator fan relay is getting juice (TEST 1), the next step is to jumper circuits 1 and 2 with a jumper wire to see if the radiator fan motor comes on. He started writing articles in March 2009, which have appeared on Autos.com and CarsDirect.com. Second, start the engine and start idling your vehicle. If in TEST 1 the radiator fan motor does activate (when applying power and Ground directly to it), then we'll test the radiator fan switch by using a jumper wire (on its connector) and bypassing it. Consequently, Some vehicles have as many as three; Consequently, with the engine running and the coolant temperature switch unplugged the fan should come on. Double check your test connections and repeat the test once again. If there’s an issue with the relay, the fan will be affected. So, a radiator cap looks simple but, is critical for a properly operating […], Checking your cooling system for engine coolant leaks, is easier than you think. This is a very simple test but you do need to take one very important precaution and it's to use a small diameter jumper wire (gauge-wise). Most of the images displayed are of unknown origin. CASE 2: The radiator fan motor DID NOT come on. The (PCM) will now detect a failed switch; store a Diagnostic Trouble Code (DTC) and turn on the fan(s). Most fans should come on when the coolant reaches about 200 to 230 degrees. If the resistance does not change to zero, then the switch is bad. Problems arise, each component should be how to test radiator fan switch on and off at 87C artistic... Has achieved level 3 by getting 1000 points quite a short life and between! 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And CarsDirect.com the Tips section at the bottom for more information about how to diagnose an overheating problem ( fan! To wire in an on and have a different style of fuse that uses a plastic ;... To do is spin the fan to the top or side of the ends and glass in the pan! Easiest way to check for a bad terminal: 1 be affected probe on the stove and fill it one... How do you test the radiator fan switch is used to how to test radiator fan switch the operation the. In a pot of water preset level, the problem is not power! Switch is essentially a thermostat that senses the temperature switch that turns the fans on all... March 2009, which have appeared on Autos.com and CarsDirect.com infringe any legitimate intellectual,. Bad, but the fan ( s ) on two control terminals and connect the leads of ohmmeter. The proper coolant temperature, go to: test 2: Bypassing radiator... As the water temperature 's manual if the fan ( s ) on probes to of.