how to test a relay without a multimeter

Just a random guy who likes to build things. Level up your tech skills and stay ahead of the curve. A relay can range in price from $5 to several hundred dollars, depending on what it controls. The energized open relay will measure nearly 0 ohms, while the closed relay will be OL or Open.If you are unable to diagnose the relay after these steps, you might need further help from a professional. Sometimes overheating prevents proper current flow in a circuit. Reusable. So, be careful to check the relay diagram before testing. Using an ohmmeter set to R X 1,000, place your leads on either of the contactor terminals. The positive jumper wire must be disconnected, and the electromagnet coil should be energized. We will test pins 30 and 87a. Ricardo has over 10 years of electrical and construction experience and his partners have over 30 years of relevant experience. Turn a multimeter to the "Ohm" setting. Here's How To Test a Relay Let's get started! Take the voltmeter and place it in the ohm () reading and set the lowest range of the ohm scale. With the use of a 9-12V battery across the pins, energize that magnetic coil. Here is a video on how you can test a Relay with or without a diagram. All Rights Reserved. [1] Method 1 Preparing Your Relay 1 Do a basic visual inspection of the relay. Therefore, the circuit is opened. Now listen to the horn beep, if the horn does not beep then the horn is faulty. To test pins 30 and 87, first, ensure that the DMM is switched to resistance mode. You can also test pins 30 and 87 by using a multitesterin linking mode. If you decide to go this route, make sure you clean off the connectors and inspect them while you have the relay removed. Because the relays involve electricity, you dont want to use them anywhere that there are flammable gases. In conclusion, the relay is an electromagnetic switch for controlling high current devices with the low current circuit. To test the terminals of it with a multitester, you will need to set the DMM to measure either low current or high or very low resistance. If the light bulb illuminates, then the relay is correct. While it is simple to test automotive relays, there are some important safety precautions you should take. Caution: Do not use an ohmmeter to measure ohms while communicating with a live wire. Save my name, email, and website in this browser for the next time I comment. The only tool required to check a relay is a multimeter. When we apply a low voltage (and low current) signal across the coil, it becomes an electromagnet and pulls the armature towards itself. You dont need a lot of tools to test an automotive relay. There are both analog and digital models available in the market. Once you are through, you should always assess regularly the installation for any sign of damage and faults. I have a problem with my car air condition system not working. The controlled circuit does not operate as expected: 2. One unfortunate and important note for this test is that a capacitor that has lost some capacitance may test okay, however, it may no longer function properly. In order to be accurate, you can try several times to get the average value. Step 2. 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. Check for discontinuity between N/O contacts and the pole. You should ensure that all the intermediate switches are switched to available positions when it comes to lighting circuits. A common end is a that is used to connect the power source toit. First of all, check the relay location. It can save you valuable time and allow you to stay focused on the task at hand without looking for instruments during the process. Keep reading to learn how to test a solid state relay! It is usually labeled as terminal 87 in itswiring diagram. Pull the wire connectors off of the capacitor with needle-nose pliers. Our team has observed that some motorbikes/ mopeds which are available in the market have starter relay problem more often Yamahas starter relay is at top. First, never replace relays with parts from another car or something you have lying around. You may also check other multimeter test learning guides below; References(1) control system https://www.britannica.com/technology/control-system(2) garbage https://www.learner.org/series/essential-lens-analyzing-photographs-across-the-curriculum/garbage-the-science-and-problem-of-what-we-throw-away/. With the Multimeter Prepared, Test the Circuit Take the multimeter and attach it to a ground. If the relay does not make a clicking sound, then proceed to the next step. As this value of resistance varies with different types of relays available in the market]. (2). Connect the leads on the switch pins. Relays are commonly utilized to control a higher-current circuit from a low-current circuit. During the test on the Five pin relay, if the value of resistance is too low or near zero, then the pins are working properly. His passion for auto electrics and his ability to solve technical problems quickly and efficiently is what sets him apart. That click just means that the coil circuit is working fine, but it never means that the relay is in its best condition. Do not use an ohmmeter when the high amperage path is connected to the source of the power. Any content contained in this website may not be copied in part or in full without express written permission from the publisher. This article has been viewed 825,674 times. On the back of the lid of these boxes, you may find markings showing the relays they house and a short description of each. Then, connect a test light between the ground and the switch terminal. RELATED: 5 Symptoms of a Bad Fuel Pump Relay. A continuity tester is a small device that is powered by batteries. There are two ways to test a relay using a multimeter. 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). This gives me a unique ability to give you expert home improvement and DIY recommendations. These components are responsible for every system, from the headlights to the air conditioning. When you remove the jumper, the light should go off. When using continuity tester on any device linked to a circuit wiring, you should always switch off the power to your circuit or your device you intend to test for continuity. Next, high-impedance test lamps are slightly more expensive, costing between $20 and $40 on average. The main difference between a relay and a regular switch is thatit uses an electromagnet to close or open its contacts, whereas a switch relies on mechanical movement to complete or break a current path. The relays should be open, switched to OL, and closed (0.2 , the internal resistance of the ohmmeter) when control power is applied. document.getElementById("ak_js_3").setAttribute("value",(new Date()).getTime()); document.getElementById("ak_js_4").setAttribute("value",(new Date()).getTime()); Copyright 2023 | Powered by Easy Car Electrics. If the multimeter reads Open or Out of Range, it could mean a defective coil winding. The resistance of the coil circuit is approximately 50 to 120-ohm value between coil circuit pins. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/4\/4f\/Test-a-Relay-Step-2-Version-2.jpg\/v4-460px-Test-a-Relay-Step-2-Version-2.jpg","bigUrl":"\/images\/thumb\/4\/4f\/Test-a-Relay-Step-2-Version-2.jpg\/aid1420038-v4-728px-Test-a-Relay-Step-2-Version-2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"