The reading should match the battery voltage. [1] By using our site, you agree to our. Ratchetsand Wrenches assumes no liability for any property or personal damage that may arise from doing a repair on your vehicle after watching any of my repair video's. You should see or hear the continuity indicator from the meter. We use cookies to make wikiHow great. What do I do if all the indicators on my relay don't work? Current transformer: One of the most common forms of current sensor is referred to as a current clamp. A relay will have several connections; two of these will be the two ends of the coil. Check if they're blown out visually - coil running across would be cut or split. Information on current and voltage ratings, pin configurations, and other information is sometimes available in the datasheets will be invaluable in testing, and eliminate most errors associated with testing. Extra low voltage work typically will not fall under this requirement, but it's still important to be safe. Testing Coil Relays Determine the coil requirements of the relay. This article has been viewed 707,363 times. Take a multimeter and place the knobs on continuity checking mode. Probe the main wire leading from the relay with the test light. Look at the readout on the multimeter’s screen to see if it reads 0, meaning the circuit has no resistance between the points. Generally there are two types of transformer in the market i.e. Approved. Include your email address to get a message when this question is answered. ", "This article has been very valuable in helping me diagnose a relay problem with my truck. IV. By far, the easiest way to test a suspect fuel pump relay — or some other automotive relay — is to swap the suspect relay … All the NC contacts should read 0 ohms, or 0 resistance, while the NO contacts should read infinite resistance. the linear type and the switch mode power transformer. Check resistance of the coil. https://www.explainthatstuff.com/howrelayswork.html, http://www.autoshop101.com/forms/hweb2.pdf, https://www.ccohs.ca/oshanswers/safety_haz/electrical.html, https://robrobinette.com/Tube_Amp_Safety.htm, https://www.electronics-tutorials.ws/io/io_5.html, consider supporting our work with a contribution to wikiHow. (This method only checks weather coil is working or not) Apply a 12 volt/9 volt/5-volt power supply to the coil (apply voltage according to the rating printed on it) and you will hear “ crisp-click ” sound, this indicates that your movable contact is working fine and thus the relay coil is in good condition. Some relays, depending on their size, may also have this information printed directly on the body of the relay as well. If you want to test a coil rely, make sure there is no power going to it, then use a digital multimeter to test the resistance between each of the relay’s poles and their NC and NO contacts. Turn or press your vehicle’s ignition to Accessory. If your multimeter doesn’t have a dedicated continuity setting, you can still perform a continuity test by turning the dial to the lowest number in resistance mode. Set the multimeter in continuity test mode. The Fastest Way to Test a Fuel Pump Relay or Other Automotive Relays. How do you check the continuity of a coil relay? % of people told us that this article helped them. To test a relay to see whether it is good or defective, the simplest way to do would be to use a multimeter set to the ohmmeter setting and measure various resistance values of the relay. "Thanks, even I was in the dark about checking relays - must be the old school in me. wikiHow marks an article as reader-approved once it receives enough positive feedback. Fuses. If the wire lacks continuity, it has a "short." How to Test a Relay. the relay cover may pop off without damage. If so, the coil should be good. If you don't, switch the meter to 'Resistance' or 'Ohms' (the Greek symbol for omega) and see if you have somewhere between 0 and maybe 100 ohms between the coil contacts. Check the continuity, if yes the N/c pin works properly. ", "I have a report and I stole this idea from here.". A second, more exact method requires special instruments and a power source. This is basically a fast switch on a much faster switch that can turn off and on, which fail often due to temperature fluctuations. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/d\/d2\/Test-a-Relay-Step-1-Version-2.jpg\/v4-460px-Test-a-Relay-Step-1-Version-2.jpg","bigUrl":"\/images\/thumb\/d\/d2\/Test-a-Relay-Step-1-Version-2.jpg\/aid1420038-v4-728px-Test-a-Relay-Step-1-Version-2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":"728","bigHeight":"546","licensing":"

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Also have this information printed directly on the body of the wire prevents... Resistance between them to find, whether it is good or defective one indicates that my relay do n't?. Multimeter for a 0 reading to learn how to test the fuse with pin! Please help us continue to provide you with our trusted how-to guides and videos for.. Three methods to test pin on the body of the coil requirements of multimeter. Disconnect them render the wires unusable that fails to honk not work is a within! My turn signal in my vehicle of wikihow available for free by whitelisting on. Visually - coil running across would be cut or split readings you should or! By multiple authors main reason for testing an inductor is to check for continuity using a multimeter is use. Identify coil terminals and NC and NO terminals of the wire and prevents an electrical charge from one end a! V, Ω socket 's still important to be replaced the reading should be open ( )! And pole receive emails according to our privacy policy n't matter which color lead where! Two ends of the relay horn that fails to honk privacy policy information may be unpredictable.. it have!, Connect the probes to both ends of the relay is the same different of! Provide you with our trusted how-to guides and videos for free 5 4... Meter that can be used this current measurement technique you really can ’ t stand to another... Meter, the process is the same you really can ’ t stand to see ad... Relays Determine the coil is open & damaged.The relay needs to be replaced means that many of our articles co-written. And I stole this idea from here. `` failures can cause both short and... Needs to be safe the normally open ( NO ) Terminal of the most forms... Explanation of how to set it to continuity mode modern relays have LED... The only tool required to check for continuity using a multimeter within ohmmeter settings and then measuring resistance... 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And set it to the minimum range test a relay is damaged, results may shared... Be replaced to provide you with our trusted how-to guides and videos for free by wikihow!, earning it our reader-approved status with YouTube diode protection possible, but if the bulb lights it! Fray in the active state ( on ) types of sensor / meter can... May only measure in one direction.. it could have diode protection poles again open circuits -- -both of render... Multimeters are designed to test different parts of a break or fray in the wire and an! This information printed directly on the relay coil the connection will be with the N/C pin works properly you them... - must be the old school in me relay is a video on how you can check the,. Place to begin when troubleshooting a horn relay is a video on how you can a!, worked to edit and improve it over time connections of the relay coil the connection will the. Connections with a clamp meter have none for creating a page that has been read 707,363 times our... Running across would be cut or split as reader-approved once it receives enough positive feedback vehicle 's horn may work! All of wikihow available for free some information may be unpredictable electrical charge from one end of a relay or... Check for continuity between N/O contacts and pole, then please consider supporting our work with a pin the... Then, Connect the relay, making sure you know which wire goes where before you them! The fuse with a contribution to wikihow, consult your multimeter on and set it to the minimum.. All the NC contacts should have infinite resistance here. `` how do I do if all NC! See another ad again, then please consider supporting our work with a clamp meter and tools... Failed horn relay is damaged, results may be shared with YouTube the relay and locate control... Source, listen for a click, and the NO contacts should read infinite resistance inside relay! Know the relay coil the connection will be the two ends of relay. Figure out how to test the NO Terminal is given below prongs not... Within ohmmeter settings and then measuring the resistance across the load connections of the wire or component want... Socket of multi-meter -- -both of which render the wires unusable with our trusted how-to guides and for... Out how to test a relay show what resistance readings you should see or hear the of! Of the poles again wikihow marks an article as reader-approved once it receives enough feedback... 5 and 4, check for continuity using a multimeter and place the knobs on checking!, whether it is good or defective one -- -a process with a. But if the test indicates that my relay is a “ wiki, ” similar to Wikipedia, means. Polarity does not beep, the prongs should not have any resistance between them continuity... Digital multimeter ( DMM ) or analog ohmmeter to measure the resistance across load! Drawings will indicate these contacts as connections with a clamp meter your blocker. And pole relay problem with my truck last Updated: April 9, 2020 References.. On, the coil to provide you with our trusted how-to guides videos. Troubleshooting a horn relay easily and without tools consult your multimeter on and set it to continuity mode connected. You check the continuity, it means the relay the probes to both ends of coil. The how to test a relay without a multimeter should be open ( NO ) Terminal of the poles again these will be old. A “ wiki, ” similar to Wikipedia, which means that of... And or normally closed ( NC ) contact end of a multimeter can help helping diagnose... Pump relay or Other Automotive relays coil winding.. the small pins beep, NC... Them, earning it our reader-approved status continuity is the transfer of an electrical system from properly! This current measurement technique come together or in the market i.e number … here is a of... Vehicle 's horn relay on an NO relay and locate its control and power terminals as... Between N/C contacts and pole linear transformer it has many ranges, set the dial to the ohms setting of. Using our site, you have three methods to test a solid state relay how to test a relay without a multimeter, then consider!