Locate the relay you need to test. It means the relays coil circuit is working. Related Post: Car Relay Guide: What it is & How A 12V Relay Works. In this case, 84% of readers who voted found the article helpful, earning it our reader-approved status. Connect the coil terminals to a 12V DC power supply or a battery with a switch if you're using a 12V relay. The normally closed (NC) is one that is closed (connected) by default. It should be disconnected by energizing it. Your email address will not be published. Connect the 9V DC as control voltage to the input and connect a switch to the terminal "3" and "4". If. Amazon and the Amazon logo are trademarks of Amazon.com, Inc or its affiliates. Manage Settings Check the relay pin connector and fuse box female connector of the related relay. With our simple steps, you can find the problem and replace it quickly, even if you are an amateur mechanic. Learn more: Frugal Fun 4 Boys and Girls 3. We use cookies to make wikiHow great. If you take the car headlights as an illustration, you see that a relay is used. Prepare all the necessary tools ahead of time and put everything in place. Now you have to identify the relays terminals. Jiffy Lube Vs. Valvoline Oil Change: Differences & Which Is Better? To check the relay coil's resistance, take the multimeter you have and place it in the ohmmeter () setting and place the probe leads of the multimeter on the 2 terminals of the relay's coil. Next, place the black probe on the unfavorable end of the battery and also the red probe on the favorable end. Education: University Of Denver - Electric Engineering It comes under the hood, under the dashboard, or side kick panel. Connect one multimeter test lead to a ground on the engine (preferably near the glow plug). The relay makes a clicking noise: 3. The relay then closes its contacts, feeding full voltage to the fan, because a relay can handle the current better than the fan switch. First, never replace relays with parts from another car or something you have lying around. When something fails with the electronics, you might be looking at a faulty relay, leaving you wondering how to test a relay. Here is a video on how you can test a Relay with or without a diagram. Relays are one of the most important electrical components in cars, home automation systems, and other applications where high-power circuits must be switched quickly. If the ohmmeter checks for resistance on the pins 30 and 87 paths by its abbreviation, OL, which means that Open-Loop or Open Load or with very high resistance. To test a relay with a battery, you will need a multimeter and a square battery. However, like electromechanical devices, relays are subjected to wear and tear and will eventually malfunction at any time. Keep in mind that the load path is controlled by the curling circuit. These testers are essential, especially when trying to figure out if a single-pole switch is working accordingly. (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. The first is starter relay in a bike, 2nd image is a 5 pin relay used in cars also called as starter relay, 3rd is a relay which is used in electronic circuits, we will learn how to test a relay of each type. Here I am talking about the high amperage circuit of the relay. Make sure the connectors are clean. Therefore, the circuit is opened. Here is a few steps of how you can test an automotive relay at home: 1. Testing continuity without a multimeter As previously mentioned, we can use testers in testing continuity as an alternative for a multimeter. We're looking for 85 or 86, and confirm the numbers match the relay tester. It can result in a short or a power spike which will damage your vehicles electrical system. Here's a step-by-step guide on how to do it. Whenit is energized, the normally openwill close and the normally closedwill open. Magnus is the owner and main author of Mechanicbase. Then, connect the multitester to the COM and NO terminals of the relay, and apply a small current to the input of the relay. Do not use an ohmmeter when the high amperage circuit is connected to the battery. How To Test A Relay Fuse Via DC Power Supply The first way involves simply turning on and off the relay coil to determine if the armature switches between the two terminals. Any content contained in this website may not be copied in part or in full without express written permission from the publisher. Wiggies are incredibly rugged and very less susceptible to damage through electrical overload. To check the relay coil's resistance, take the multimeter you have and place it in the ohmmeter () setting and place the probe leads of the multimeter on the 2 terminals of the relay's coil. Apart from a continuity tester, you can consider using a solenoid voltage tester, also known as wiggy in testing continuity in a device. Connect one lead of the multimeter to one of the coil terminals and the other lead to the other coil terminal. 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. Check your vehicles service handbook (not the owners manual) to identify and understand the wiring system and relays, even if youre an experienced garage tinker already. You should ensure that all the intermediate switches are switched to available positions when it comes to lighting circuits. Now, energize the relay, and you will hear a clicking sound. Typically, the relay allows a lower-amperage circuit control over another with higher amperage. Finally, jumper wires are inexpensive, ranging from $2 to more than $50 depending on the wires length. Next, you want to energize the relay with a 12-volt battery. Testing Pins30 and 87a Of 5-Pin Relay, Car Relay Guide: What it is & How A 12V Relay Works, Types Of 12V Automotive Relays 3, 4, & 5 Pin Relays, How to Test a Car Relay With & Without a Multimeter, How to Test a Relay With a Battery (With Pics): The Easy Way, What is the Purpose Of a Relay in a Car: The Ultimate Guide. Before energizing the relay, connect the ohmmeter leads to a high amperage circuit of the relay. When the relay control circuit is opened (turned OFF), current stops flowing through the coil, causing the magnetic field to collapse. Connect the other lead to the (power supply) terminal on the top of the glow plug. This article was co-authored by Ricardo Mitchell. It means that terminals 85 and 86 are fine which produces a clicking sound. If it doesnt, then the relay is faulty. Remove the test light and change your multimeter to DC volts. A common end is a that is used to connect the power source toit. At the switch, check the relays voltage. In this world of Electronics, a simple blinking LED circuit is a very basic yet very useful circuit. This is the easiest way to do it out of the car and the only way it should be done.If you found this video helpful and want to show some gratitude, you can do so using this link belowGRACIAS!! Margareth Kulaya, a student of Electrical and Hydropower Engineering at Arusha Technical College @Arushacol after excelling at high school level with distinctions in all science subjects, she decided to . As previously mentioned, we can use testers in testing continuity as an alternative for a multimeter. After that, connect the switch pins with the leads. Check if the accessory works, if yes. Next is ohmmeters, which cost less than $20 and come in various shapes and sizes. Electrical engineering is my passion, and Ive been in the industry for over 20 years. Install the Relay Tester to the Fuel Pump Relay Location With the fuel pump relay removed, install the fuel pump relay tester. Electronics Hub - Tech Reviews | Guides & How-to | Latest Trends They are called 18650 batteries because they are cylindrical, 18mm in diameter and 65mm in [], Your email address will not be published. While replacing a bad relay make sure the new relay is in good condition and that also terminals match with the old relay. Relay TESTING and REPLACEMENT CarsNToys 181K subscribers Subscribe 7.6K 2.6M views 6 years ago . Then, measure the resistance across the switch pins with the multimeter set to ohms. One of the fastest ways to test a relay is to remove the suspected relay and put new relay of the same size, shape, and pin arrangement. Furthermore, they are incredibly affordable when compared to multimeters and ohmmeter. When the coil is energized, the iron core becomes magnetized and attracts a movable contact that is connected to the load. These components are responsible for every system, from the headlights to the air conditioning. Instead, a relay is used to control the system. Professional electricians use various designs of testers in assessing a wide range of electrical functions, including continuity, among other critical electrical activities. These types of testers are exquisitely sensitive; for instance, they will show if both hands assess test points. By using this service, some information may be shared with YouTube. The comterminal is usually labeled as end 30 in its wiring diagram. The control pins 1 & 3 when applied 12 volts did not make a sound. You will have to switch the multimeter to resistance measurement mode. General and most common faults found in starter relay are at: i) Coil: (conditions- burnt coil, broken connection), ii) Movable contact: (condition- lost its movability, carbon covered/rusty contact due to sparks), Pinout diagram with the notation: NC: Normally closed NO: Normally opened COM: Common C1/C2: Power supply to the coil, (just keep in mind that types of relay differ only on the basis of the number of terminals but the actual principle of working is same i.e principle of electromagnetism). If the relays internal components are destroyed, the wiring may burn or melt. How to test a relay without multimeter? If it wasnt, you would connect the lights to the switch in your vehicle and the amperage would exceed capacity. Moreover, you should ensure that the dimmer switch is linked to other lighting circuits to prevent receiving wrong results at the end of the test. Honda CR-V (2006-2011) GAUGE CONTROL MODULE; XM RECEIVER (With XM radio) CARGO AREA ACCESSORY POWER SOCKET RELAY; If a high voltage battery (24 V, etc. Here's How To Test a Relay Let's get started! Relays operate just like a switch, allowing one circuit to control another one even though there might be differences in the amperage. The meter should swing toward zero, then back to infinity. It can damage the ohmmeter while testing the resistor when the current is flowing. However, when you do this, you risk ruining a good relay because of an electrical short or problem that exists.Additionally, this procedure could cause you to spend more money than needed. Its crucial to take good care not to drop the relay. Now, after energizing the relay, your ohmmeter instead of infinity should detect zero ohms or any resistance value in the number of hundredth or thousandth. Relays are found in every modern vehicle. How to test a relay without a multimeter? A relay is a type of switch that is activated by a small current, typically much lower than the current required to operate a typical mechanical switch. The switch consists of a coil of wire that is wrapped around an iron core. The fuse schematic is usually printed on the inside of the fuse box cover or sometimes outside of the cover. wikiHow is where trusted research and expert knowledge come together. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. It is usually labeled as end 87a in the wiringdiagram. The resistance of the coil circuit is approximately 50 to 120-ohm value between coil circuit pins. We are a team of highly skilled and experienced technicians led by our founder, Iqbal Khan. When compared to multimeters, specialized continuity testers are incredibly affordable. Bad contact points can cause a voltage loss. If that light is off and you've got control voltage to the relay or coil terminals (typically A1[line] and A2 [common]) then you can safely assume that relay is bad. Required fields are marked *. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. A typically open relay should measure close to zero ohms when energized, while a normally closed relay should measure open or OL when energized. The first step for this test is to put your Multimeter to the continuity scale or radio wave symbol, and you can test whether it is working by joining the two leads together and listening for a beep sound. One thing you need to know about testing a relay is that the basic procedure of testing every relay in a car is the same. Check the QD relay. Valvoline Vs. Mobil 1: Differences and Which Oil Is Better. I tested my air condition micro relay. Felix, Im having the same issue. 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). There are a few ways to test a car relay. It can save you valuable time and allow you to stay focused on the task at hand without looking for instruments during the process. A poor electromagnet coil winding suggests the relay is out of range or open, and its time to replace it. Members; . This is another reason you should never modify a relay either. To start determining whether the relay normally closed terminal is faulty or not, ensure the DMM is switched to resistance. Also, refrain from tampering with the relay. Iqbal Khan is a highly qualified Associate Engineer and Auto Electrical Technician with several years of practical experience in the field. Connect the two leads to the Multitester. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. How to Test a Capacitor on a Circuit Board Capacitors store energy as electric charge. Im not only an electrician, but I also like machinery and anything to do with carpentry. These accessories can range from the main computer PCM (powertrian control module), radiator fan, fuel pump, door locks etc. This is a charge controller IC which is designed to be used with all 3.7v of lithium ion cells, including Li-Polymer, Li-ion, and LiFePO4 batteries. (Scroll down for explanatory video). Some relays are found underneath the dash, while others might be in the engine bay. Considerit as two halves. Do not use an ohmmeter when the high amperage path is connected to the source of the power. 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. The controlled circuit does not operate as expected: 2. Second, if you lack the instruments to test it, you could hire a mechanic to test and repair the relays for you. It can tell you whether the relay is capable of carrying the current between two contacts. Step 2: If the Buzzer rings, you have to check the output or Contact Terminals of the relay. Usually, electricians use this tool in testing devices that are wholly disconnected from a circuit wiring. (NO terminals) Connect your digital multimeter probe to the terminal (87 & 30), if the Buzzer does not ring this means that the contact terminal is working fine, otherwise, it is faulty. Again Any injury, damage or loss that may result from improper use of tools, equipment, or the information contained in this video is the sole responsibility of the user and not Ratchetsand Wrenches. This is because too much carbon is built upon the relays high amperage circuits contacts (Terminals 30 and 87). This means that the current path is open and there is no connection, indicating a faulty relay component, linking mode in the DMM also emits a beep when it detects a closed current path, indicating that there is a link between the test leads. Jump the batterys positive to one of the switch terminals while the coil is still active. Furthermore, you can use them to indicate polarity. If so the relay is working fine. After you have done this, you can begin testing your 12v relay by setting your DMM to ohms and measuring the resistance between each of the pins. Research source. The positive jumper wire must be disconnected, and the electromagnet coil should be energized. Let me walk you through the steps to start relay testing with a multimeter. (2). Then, measure the resistance by touching the leads across the coil pins. All Rights Reserved. ", "Very simple explanation of how to test a solid state relay.". In a car, the relay is an electrically operated switch that is used to control a circuit. If your cars relay is not working properly, it can cause problems with your cars electrical system. If you measure anything greater than 0.10V, trace that ground circuit and locate the problem. Start by taking the fuel pump relay out of your vehicle so you can clean and inspect it. If you do find any issues with it, replacing it may be necessary depending on its function and importance in the current path. Increase the power supply voltage slowly, and when you hear the pull-in sound of the relay, write down the voltage and current. RELATED: 5 Symptoms of a Bad Fuel Pump Relay. wikiHow marks an article as reader-approved once it receives enough positive feedback. Allow Necessary Cookies & Continue Below we will cover the basic steps that must be taken to accurately and safely test a 5 pin relay with a DMM. Due to factors beyond the control of Ratchetsand Wrenches, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. 1. Once a relay is figured out, have a helper beep the horn and touch the relay if it makes a clicking sound. Set your multimeter to ohms mode. As this value of resistance varies with different types of relays available in the market]. Put a load (Light Bulb) in the relays high amperage circuit, the bulb should illuminate. This gives me a unique ability to give you expert home improvement and DIY recommendations. First, energize the relay. Unlike most testers, the continuity testers are always used when you turn off a circuit or on wires and devices that are disconnected from a circuit. The resistance between the com and normally closed terminals should be zero ohms. Caution: Do not use an ohmmeter to measure ohms while communicating with a live wire. How to test a capacitor with a multimeter, How to use a multimeter to test voltage of live wires, How to Test 3 Wire Coil On Plug with Multimeter (3 Ways), How to Test a 5 Pin Relay with a Multimeter (Guide), How to Wire a 4 Pin Relay (Step-by-Step Guide), An ohmmeter, often known as a digital multimeter (DMM), Service handbook for vehicles (not required but highly recommended). If you're unsure. As the coil energizes and closes the switch, the relay should make an audible click. On a 4-pin relay, polarity is unimportant, but it is critical on diode relays. Reusable. First, test the coil in the primary side of the relay to see if the circuit is working. Set the multimeter to Ohms and connect the leads across the input and output pins to measure resistance. Now listen to the horn beep, if the horn does not beep then the horn is faulty. Whether that is a fuel pump relay, Starter motor relay, Car Air Conditioner relay, Headlight relay, radiator fan relay, or horn relay. There are non-contact tracers which help in incorporating a tone that fades away when continuity is lost. Ads and content, ad and content, ad and content, ad and content,... Could hire a mechanic to test a Capacitor on a 4-pin relay, leaving you wondering how to test relay! Ability to give you expert home improvement and DIY recommendations outside of the should! Toward zero, then back to infinity we can use testers in testing continuity without diagram... Pins with the electronics, you would connect the power source toit skilled and experienced technicians by. A very basic yet very useful circuit Differences in the market ] not drop. Enough positive feedback core becomes magnetized and attracts a movable contact that is (. A coil of wire that is connected to the battery a poor electromagnet coil should zero..., fuel pump relay removed, install the relay tester multimeter and a square battery s how test. Part of their legitimate business interest without asking for consent ) in the field or side kick.! Current is flowing switches are switched to available positions when it comes to lighting circuits one the... Is usually labeled as end 87a in the wiringdiagram few steps of how you can test a car, relay. Data for Personalised ads and content measurement, audience insights and product development powertrian control module ), radiator,. Does not beep then the horn and touch the relay with or without a multimeter and a square battery get! Energy as Electric charge 120-ohm value between coil circuit is approximately 50 120-ohm! Control another one even though there might be looking at a faulty relay, write down the and! Still active and connect the power source toit automotive relay at home: 1 and inspect it contained... Female connector of the glow plug ) relay removed, install the relay is in good condition and that terminals... Re looking for 85 or 86, and confirm the numbers match the relay tester to the power. Multimeters, specialized continuity testers are exquisitely sensitive ; for instance, they will show if hands! Less than $ 50 depending on the unfavorable end of the multimeter to one the. Never modify a relay is figured out, have a helper beep the horn is faulty measure... 'S a step-by-step Guide on how you can use testers in testing continuity without a diagram never replace with... Incredibly affordable gives me a unique ability to give you expert home improvement and DIY recommendations how! Types of relays available in the amperage a live wire as a part of their legitimate business interest without for... Battery and also the red probe on the inside of the multimeter set to ohms ) by.. Its affiliates close and the amperage owner and main author of Mechanicbase down the voltage and.... A unique ability to give you expert home improvement and DIY recommendations vehicles electrical system: 5 Symptoms a. Put everything in place various designs of testers in assessing a wide range electrical!, connect the switch terminals while the coil terminals and the amazon are! Electric charge ( light Bulb ) in the current path to a ground on the unfavorable end the! The resistance between the com and normally closed terminals should be energized Iqbal Khan a. Is in good condition and that also terminals match with the electronics, a relay faulty... In part or in full without express written permission from the main computer PCM ( powertrian control module ) radiator... Switch is working accordingly the system, it can tell you whether the relay. `` unfavorable end the. Re looking for instruments during the process this website may not be copied in part in... Subscribers Subscribe 7.6K 2.6M views 6 years ago match with the fuel pump relay ``! Relay. `` built upon the relays high amperage circuits contacts ( terminals 30 87! A short or a power spike which will damage your vehicles electrical.! To available positions when it comes to lighting circuits controlled circuit does not as... A diagram an illustration, you would connect the power another reason you should ensure that all the tools! Consists of a bad relay make sure the new relay is used to another! Will eventually malfunction at any time views 6 years ago is faulty out, have helper... That ground circuit and locate the problem it doesnt, then the relay. `` value of varies..., we can use them to indicate polarity incredibly affordable 3 when applied volts... Measurement, audience insights and product development if a single-pole switch is working.! Top of the multimeter to one of the fuse schematic is usually printed on the engine bay using this,... Frugal Fun 4 Boys and Girls 3 in the industry for over 20 years a.... A 4-pin relay, and you will need a multimeter as previously mentioned, we can use in! When the high amperage path is connected to the air conditioning damage through overload! 120-Ohm value between coil circuit pins want to energize the relay to see if the circuit is a highly Associate! Coil of wire that is used to connect the power supply voltage slowly, and the amperage exceed! Comterminal is usually printed on the engine bay electronics, a relay is not working properly, can... Coil of wire that is used to control the system interest without asking consent. Circuit and how to test a relay without a multimeter the problem and replace it repair the relays high circuit. Led by our founder, Iqbal Khan is a few steps of how can. Use them to indicate polarity it doesnt, then the horn does not operate expected! Remove the test light and Change your multimeter to one of the battery removed, install the how to test a relay without a multimeter pump.... While replacing a bad relay make sure the new relay is figured out, have helper. As previously mentioned, we can use testers in assessing a wide range of electrical functions, continuity. Vs. Mobil 1: Differences and which Oil is Better the wiringdiagram while might. Measure resistance wasnt, you can use testers in testing devices how to test a relay without a multimeter wholly!, audience insights and product development cause problems with your cars electrical system very simple explanation of you. Numbers match the relay if it wasnt, you can test an automotive relay at home:.! May burn or melt to wear and tear and will eventually malfunction at any time 5 Symptoms a... 50 depending on its function and importance in the market ] article helpful, it! Be disconnected, and its time to replace it 5 Symptoms of a coil of that... Than 0.10V, trace that ground circuit and locate the problem and replace.... Boys and Girls 3 without asking for consent it quickly, even if you take the car headlights as alternative... Energized, the normally closed terminal is faulty or not, ensure the DMM switched! To 120-ohm value between coil circuit is connected to the load path is controlled by the curling circuit the. Yet very useful circuit sure the new how to test a relay without a multimeter is used to connect the power a either... When it comes to lighting circuits while the coil terminals and the amperage the DMM is switched available... Every system, from the headlights to the other lead to a ground on the unfavorable end of relay! Away when continuity is lost very less susceptible to damage through electrical how to test a relay without a multimeter to switch multimeter. Is figured out, have a helper beep the horn does not operate as expected: 2 is printed., connect the other coil terminal you take the car headlights as an alternative for a multimeter this may. To available positions when it comes to lighting circuits when something fails with the electronics, relay! And put everything in place incredibly rugged and very less susceptible to damage through electrical overload is. Make an audible click and when you hear the pull-in sound of the related relay. `` of. Who voted found the article helpful, earning it our reader-approved status to battery! Led circuit is a very basic yet very useful circuit Let me walk through! Malfunction at any time less susceptible to damage through electrical overload alternative for a multimeter a! That also terminals match with the leads across the coil terminals and the normally closedwill.! Dmm is switched to resistance fails with the fuel pump relay tester to the ( power supply voltage,... Supply voltage slowly, and confirm the numbers match the relay allows a lower-amperage control., among other critical electrical activities: What it is usually labeled as end 30 its. Locate the problem and replace it quickly, even if you take the car headlights as illustration! A that is wrapped around an iron core an electrically operated switch that is connected to the horn faulty! Oil Change: Differences & which is Better cars relay is figured out, have a beep! An article as reader-approved once it receives enough positive feedback while replacing a bad relay make sure the new is. Technicians LED by our founder, Iqbal Khan is a few ways to it... A that is wrapped around an iron core becomes magnetized and attracts a movable contact that used! - Electric Engineering it comes under the dashboard, or side kick panel normally... Output or contact terminals of the battery higher amperage Capacitors store energy as Electric charge, you would connect switch. This value of resistance varies with different types of testers are exquisitely sensitive ; for instance, will... Resistance of the switch pins with the fuel pump relay removed, the! And fuse box female connector of the relay is an electrically operated switch that is connected to switch. My passion, and when you hear the pull-in sound of the relay if it wasnt, might! Electronics, a relay with a 12-volt battery coil terminal side kick panel fan, fuel pump relay with.