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. Engine cooling fan, 50 amp fuse,at the power distribution center or relay box at engine compartment. 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. Check out some of my other posts if you need more tips and info." 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. 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 the leads of an ohmmeter to the power terminals on the relay. If you get infinite resistance from the ohmmeter, the relay contact points are not letting electric current flow through. How to Test a Relay. Example: Testing the radiator cooling fan relay, the cooling fan should be operating. The cooling fan relay is the relay that controls the engine’s cooling fans. As you touch ground with the jumper wire, you should hear a click sound coming from the relay. COPYRIGHT © 2021 DANNYSENGINEPORTAL.COM BY DANNY BENDER - DISCLAIMER: All wallpapers and backgrounds found here are believed to be in the "public domain". His work has appeared in Texas, New Mexico and Miami and on various websites. CASE 2: Fan motor 2 DID NOT come On. The … How to Reset the Immobilizer on a Jeep ... Photo courtesy of Leonard G. at Commons Wikimedia.org. 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. When the vehicle is not running, then there will be no air passing through the radiator. In most cases, the two thin wires connect to the control circuit and the two thick wires connect the power terminals on the relay. If you read any amount of resistance, the relay contacts are stuck closed and the relay should be replaced. Also, it may cause the A/C compressor to overheat and fail. Switch it on with a tiny current and it switches on (“leverages”) another item using a much bigger current. If no power is observed at either 87 or 30, the fusible link or maxi fuse has shorted. This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. - The … Be sure you have the right one. A valve lifter (sometimes referred to as a tappet or cam follower); follows the contour of the camshaft lobe and transfers that motion […]. Now you should read zero resistance. It is a generic code applying to all OBD II (on board diagnostics) vehicles. Go to: TEST 4. One of the first symptoms commonly associated with a bad or failing cooling fan relay is; an engine that runs hot or overheats. If the bulb in the test light glows, there is voltage, and your relay is working properly. Using your ohmmeter as described on step 2, check for continuity at the relay's power terminals. 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. The relay(s) are used to control the high current flow to power the cooling fan motors. This tells you that the cooling fan motor is fried and needs to be replaced. 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. 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. Set the ohmmeter to the lowest range. Relays bridge the gap, making it possible for small currents to activate larger ones. The fan relay controls the power to the cooling fan. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser. 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. – Why Do You Need It ? The reason being, on most vehicles, is that the cooling fan doubles as a condenser fan. Connect the leads of an ohmmeter to the power terminals on the relay. As we drive our vehicles, a sufficient quantity of air passes through the radiator, which effectively cools the engine. Leave the jumper wires connected to the relay control terminals if you heard the click sound in the previous step. 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. Another simple relay test is to shake it. You can test the cooling fan temperature switch using a test light. The engine may also run hot and overheat, too. You can think of a relay as a kind of electric lever. If resistance is high, the coil may still be working but it is failing; or it may not work when electrical loads are high. Replace the relay. This test result let's you know that fan motor 2 is OK. A cooling fan relay is used on vehicles that have an electrical fan to cool the engine. By using a lower voltage signal to control the relay, there is less stress on the rest of the wiring and charging system. 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. Engine Antifreeze Coolant – What Does It Do ? Since 2003 Dan Ferrell has contributed general and consumer-oriented news to television and the Web. 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. 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. How to Test Cooling Fan relay. 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”. Non-functional cooling fans are another common symptom of a potential problem with the cooling fan relay. 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. 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. The relay will usually be activated once it is detected that the vehicle’s temperature approaches excessively high temperatures. This means the relay contacts are operating normally. 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. Set the ohmmeter to the lowest range. 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. When … 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. But often we need them to drive bigger pieces of apparatus that use bigger currents. Checking the operation of a fan relay on your vehicle is an easy procedure. 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. So, […], The term “valve lash” is often used when discussing valve train adjustment. The cooling fan relay is the relay that controls the engine’s cooling fans. Both fans should come on when the A/C is on. Use a test light to determine if there is power in these two wires. 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. However, specific troubleshooting steps will vary depending on the vehicle. The armature is normally closed and is pulled open when energized. We do not intend to infringe any legitimate intellectual right, artistic rights or copyright. 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. The main purpose of Antifreeze Coolant in your engine is to remove heat. 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. You should read infinite resistance. While you are driving, air in sufficient quantity is passing through the radiator effectively cooling the engine. Heat/ Defrost fan fuse number 7 inside drivers dash fuse box. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser. 1. Possible Causes of a Bad Cooling Fan Relay A good relay coil will typically read 40 to 80 ohms. Copyright 2020 Leaf Group Ltd. / Leaf Group Media. You should read infinite resistance. If the cooling fans are staying on all the time, this is another (less common) symptom. A faulty cooling fan relay can also negatively affect air conditioning (A/C) performance. 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. 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? 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 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. When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans. Faulty wiring could be to blame. Watch this video to figure out how to diagnose problems with the cooling fan relay on a Chrysler. Just keep in mind that many modern cars use electronic relays. When the A/C is turned on, the fan moves air across the A/C condenser, thereby removing heat from the vapor refrigerant inside. As a result, using a cooling fan relay solves this problem. Inexpensive fused jumper wires are available at most auto parts stores. The armature closes when the coil is energized to route power to the fan motor. Most of the images displayed are of unknown origin. If the relay fails, it will be unable to supply power to the fans; and as a result they will not operate. See the Tips section at the bottom for more information. 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. Connect your test light to battery ground. A wiring issue. - The A/C clutch requested. 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. These steps only apply to electro-mechanical relays, which contain a coil and contact points as main components. If you read any amount of resistance, the relay contacts are stuck closed and the relay should be replaced. Defective fan relay. Thanks lads n gals. Finally, if you suspect that your cooling fan relay, may possibly be having issues, have it checked. The typical electric cooling fan circuit includes a temperature sensor, a relay, a control module and the fan motor. Although the water pump in most vehicles will last a long time, they are by no means indestructible. If there’s an issue with the relay, the fan will be affected. Dose anyone one know how to test the fan relay? As I say, having removed the shroud, I am at the stage where I want to test the relays in … A relay uses a relatively small electric current that can turn on or off a much larger electric current. If only one of the wires has power it is likely that the circuit from the fuse to the relay … 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. You should be able to conduct an Output Test with the ECM (key-on, engine-off). To test a solid state relay, follow figure and steps given below. Pip Ferrell is a certified automation and control technician from the Advanced Technology Center in El Paso, Texas. The next step is to test fan motor relays (all three in the engine compartment fan/relay box). This type conducts current when open and when closed in two different circuits. If you hear something rattling inside, the relay armature is probably broken. How To Install Replace AC Heater Fan Speed Resistor Chrysler Pacifica 04... 2008 PT Cruiser Fan Relay Location Why is that useful? 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. 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. A relay is basically an electromagnet (a coil of wire that becomes a temporary magnet when electricity flows through it). It may cause the fan to cut in and out, or not come on at all. 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. As the name suggests, many sensors are incredibly sensitive pieces of electronic equipment and produce only small electric currents. 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. 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. 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. Replace the relay. If You Think The Problem Is The Cooling Fan Relay, Test It ! The fan should 'ramp-up' from 0 to 100% and back to 0% speed. If the coil has no resistance, it is open and has failed. 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 will find the resistance of the relay coil. Probe the wire coming out of the relay and going to the component with the tip of the test light. If you do not hear the click sound, replace the relay.