This tells you that the cooling fan motor is fried and needs to be replaced. Copyright 2020 Leaf Group Ltd. / Leaf Group Media. A cooling fan relay is used on vehicles that have an electrical fan to cool the engine. As you touch ground with the jumper wire, you should hear a click sound coming from the relay. Use a test light to determine if there is power in these two wires. If no power is observed at either 87 or 30, the fusible link or maxi fuse has shorted. Relays bridge the gap, making it possible for small currents to activate larger ones. A wiring issue. When the vehicle is not running, then there will be no air passing through the radiator. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser. 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. Defective fan relay. The cooling fan relay essentially functions as the switch for the engine’s cooling fans; and is therefore an important electrical component of the vehicle’s cooling system. The armature is normally closed and is pulled open when energized. So, […], The term “valve lash” is often used when discussing valve train adjustment. When the A/C is turned on, the fan moves air across the A/C condenser, thereby removing heat from the vapor refrigerant inside. The cooling fan relay takes the low voltage signal and internally switches the relay “on” to allow battery voltage to be supplied to the radiator cooling fan. Connect your test light to battery ground. The fan should 'ramp-up' from 0 to 100% and back to 0% speed. Another simple relay test is to shake it. The relay(s) are used to control the high current flow to power the cooling fan motors. If you read any amount of resistance, the relay contacts are stuck closed and the relay should be replaced. If you get infinite resistance from the ohmmeter, the relay contact points are not letting electric current flow through. If resistance is high, the coil may still be working but it is failing; or it may not work when electrical loads are high. 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, Engine Coolant Leaks – How To Find Them – How Bad Are They, Valve Lifters – Hydraulic And Mechanical – What Is The Difference, Radiator Cap – Basic Function – Failure Symptoms – How Important Is It, 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, Valve Lash – Getting All The Facts For Setting And Adjustment. You do not need the Jeep factory scan tool, just a generic scan tool that you can buy at your local auto parts store or online and a multimeter. If you do not hear the click sound, replace the relay. Set the ohmmeter to the lowest range. Think mine has gone just want to test it to make sure, its a 2001, 2.5 v6 Also has the main engine fans meant to come on when the a/c is on? COPYRIGHT © 2021 DANNYSENGINEPORTAL.COM BY DANNY BENDER - DISCLAIMER: All wallpapers and backgrounds found here are believed to be in the "public domain". - The … The reason being, on most vehicles, is that the cooling fan doubles as a condenser fan. How To Install Replace AC Heater Fan Speed Resistor Chrysler Pacifica 04... 2008 PT Cruiser Fan Relay Location A relay uses a relatively small electric current that can turn on or off a much larger electric current. TIP 1: The way I've designed the Jeep PWM fan relay test, you'll need a scan tool that can read live data (not a code reader), since you'll need to keep an eye on the engine's coolant temperature with it. Check out some of my other posts if you need more tips and info." 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. Be sure you have the right one. The typical electric cooling fan circuit includes a temperature sensor, a relay, a control module and the fan motor. Engine cooling fan, 50 amp fuse,at the power distribution center or relay box at engine compartment. Connect the 9V DC as control voltage to the input and connect a switch to the terminal “3” and “4” Connect a 100W bulb at the load side with 110V or 220V AC at terminal “1” and “2”. Thanks lads n gals. Probe the wire coming out of the relay and going to the component with the tip of the test light. Oil Leak In Spark Plug Well – Know The Signs – What Can Happen, Broken Bolt – Stud Removing – Repair Tips To Save You Time And Money, We all know it’s important to take care of your vehicle’s engine; but some common engine problems can get overlooked. If there’s an issue with the relay, the fan will be affected. 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. CASE 2: Fan motor 2 DID NOT come On. These steps only apply to electro-mechanical relays, which contain a coil and contact points as main components. The cooling fan relay is the relay that controls the engine’s cooling fans. A faulty cooling fan relay can also negatively affect air conditioning (A/C) performance. The most common problem on these relays is an open or shorted coil and burned points that block the flow of electrical current after years of use. I now have the front off my 2003 1.8 turbo, which has a habit of running the high speed fan most of the time and running on when switched off. The cooling fan relay is the relay that controls the engine’s cooling fans. Heat/ Defrost fan fuse number 7 inside drivers dash fuse box. You can test the cooling fan temperature switch using a test light. Switch it on with a tiny current and it switches on (“leverages”) another item using a much bigger current. Locate the coolant temperature switch and unplug it. The Next Thing To Test Is The Coolant Switch Or Sensor On most systems; there is a coolant temperature switch that turns the fans on and off. Connect the leads of an ohmmeter to the power terminals on the relay. It may cause the fan to cut in and out, or not come on at all. As a result, using a cooling fan relay solves this problem. If the relay does not have markings on it to differentiate the control and power terminals, try looking at the wires connecting to the relay contacts under the fuse block or power junction on the vehicle. Step 4 Probe the wire or wires feeding voltage to the relay with the test light following the same procedure used on the previous step. Attach the end of a regular jumper wire to the other terminal of the control circuit on the relay and touch the other end to ground on your vehicle. 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. Now you should read zero resistance. As the name suggests, many sensors are incredibly sensitive pieces of electronic equipment and produce only small electric currents. This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. Relays are discrete devices (as opposed to integrated circuits) that are used to allow a low power logic signal to control a much higher power circuit. Checking the operation of a fan relay on your vehicle is an easy procedure. When minimum cooling is required, the BCM will command the PCM to energize cooling fan relay #1 and since both fans are connected in series through the Mode Control relay, both fans will operate at low speed. Non-functional cooling fans are another common symptom of a potential problem with the cooling fan relay. Since 2003 Dan Ferrell has contributed general and consumer-oriented news to television and the Web. To test a solid state relay, follow figure and steps given below. Both fans should come on when the A/C is on. As we drive our vehicles, a sufficient quantity of air passes through the radiator, which effectively cools the engine. If the cooling fans are staying on all the time, this is another (less common) symptom. With the relay in the configuration that has the 2 load pins connected, place the test voltage on 1 of the load pins of the relay and an automotive test light on the other load pin of the relay. Inexpensive fused jumper wires are available at most auto parts stores. 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. You should be able to conduct an Output Test with the ECM (key-on, engine-off). The armature closes when the coil is energized to route power to the fan motor. The relay will usually be activated once it is detected that the vehicle’s temperature approaches excessively high temperatures. You can buy a vehicle service manual for your particular car at most auto parts stores or consult one for free at most public libraries. Also, it may cause the A/C compressor to overheat and fail. Faulty wiring could be to blame. By using a lower voltage signal to control the relay, there is less stress on the rest of the wiring and charging system. If you hear something rattling inside, the relay armature is probably broken. Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. Replace the relay. If the bulb in the test light glows, there is voltage, and your relay is working properly. Although the water pump in most vehicles will last a long time, they are by no means indestructible. This means the relay contacts are operating normally. Pip Using your ohmmeter as described on step 2, check for continuity at the relay's power terminals. Why is that useful? If the relay fails, it will be unable to supply power to the fans; and as a result they will not operate. - The A/C clutch requested. While you are driving, air in sufficient quantity is passing through the radiator effectively cooling the engine. If you read any amount of resistance, the relay contacts are stuck closed and the relay should be replaced. It is a generic code applying to all OBD II (on board diagnostics) vehicles. When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans. So, Like any other mechanical […], Antifreeze Coolant is a mixture of antifreeze agents and water; which goes into your vehicle’s cooling system to regulate the temperature. Replace the relay. In most cases, the two thin wires connect to the control circuit and the two thick wires connect the power terminals on the relay. So, as a vehicle owner it is important that you’re; constantly on the lookout for […], To start with, Water Pump Failure can be extremely hard to diagnose. The main purpose of Antifreeze Coolant in your engine is to remove heat. A good relay coil will typically read 40 to 80 ohms. When … You can think of a relay as a kind of electric lever. If the coil has no resistance, it is open and has failed. 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. Just keep in mind that many modern cars use electronic relays. 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. A relay is basically an electromagnet (a coil of wire that becomes a temporary magnet when electricity flows through it). How to Test a Relay. We do not intend to infringe any legitimate intellectual right, artistic rights or copyright. 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. Hook one end of a fused jumper wire to one of the relay control terminals and the other end to the positive terminal of the car battery. The … Possible Causes of a Bad Cooling Fan Relay Most of the images displayed are of unknown origin. You should read infinite resistance. However, specific troubleshooting steps will vary depending on the vehicle. How to Test Cooling Fan relay. 1. The engine may also run hot and overheat, too. See the Tips section at the bottom for more information. This type conducts current when open and when closed in two different circuits. Engine Antifreeze Coolant – What Does It Do ? His work has appeared in Texas, New Mexico and Miami and on various websites. Example: Testing the radiator cooling fan relay, the cooling fan should be operating. Connect the leads of an ohmmeter to the power terminals on the relay. Dose anyone one know how to test the fan relay? If You Think The Problem Is The Cooling Fan Relay, Test It ! One of the first symptoms commonly associated with a bad or failing cooling fan relay is; an engine that runs hot or overheats. The cooling fan relay will be commanded ON when the following conditions are met: - The engine coolant temperature reaches 106°C (223°F) or more. But often we need them to drive bigger pieces of apparatus that use bigger currents. Ferrell is a certified automation and control technician from the Advanced Technology Center in El Paso, Texas. Finally, if you suspect that your cooling fan relay, may possibly be having issues, have it checked. If only one of the wires has power it is likely that the circuit from the fuse to the relay … You will find the resistance of the relay coil. You should read infinite resistance. Go to: TEST 4. How to Reset the Immobilizer on a Jeep ... Photo courtesy of Leonard G. at Commons Wikimedia.org. On most modern vehicles (late '90s and newer), you are looking for the switch that connects to your car computer (powertrain computer), since there may be more than one switch. 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. – Why Do You Need It ? The next step is to test fan motor relays (all three in the engine compartment fan/relay box). As I say, having removed the shroud, I am at the stage where I want to test the relays in … A valve lifter (sometimes referred to as a tappet or cam follower); follows the contour of the camshaft lobe and transfers that motion […]. Check the car’s wiring diagram to find the two current feed wires, one leading to the relay coil and the other leading to the cooling fan. Leave the jumper wires connected to the relay control terminals if you heard the click sound in the previous step. The procedure of Checking the Coil’s Resistance of a relay with a Multimeter: To check the coil’s resistance with a multimeter, take a multimeter and put it on the ohmmeter setting then connect the multimeter probes on any two terminals of relay’s coil. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser. If your vehicle's check engine light comes on and after pulling the code you find a P0480 displayed, if refers to the engine cooling fan circuit. The fan relay controls the power to the cooling fan. This test result let's you know that fan motor 2 is OK. 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. Common Engine Problems – Noises, Leaks, Overheating, Fuel Problems, Water Pump Failure – What Are The Common Failure Warning Signs, Antifreeze Coolant – What Are The Basics You Really Need To Know. 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