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). Usually, these specialized continuity testers are more basic in nature, and they feature small bulbs that illuminate when current flow through them. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. ", "This helped me understand a little more about how to test my cars relay. It is an important piece of equipment that can help regulate the power supply in a variety of applications. Take a 12 volts battery, connecting wires, and a voltmeter or a multimeter and set it to the volt measuring. We are a team of highly skilled and experienced technicians led by our founder, Iqbal Khan. Connect the two leads to the Multitester. 1. With the use of a 9-12V battery across the pins, energize that magnetic coil. We may receive a commission for purchases made through these links. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Your email address will not be published. These step up DC to DC boost converters are [], The TC4056 is a linear li-ion battery charger IC that is generally used in devices to charge 18650 li-ion cells. Continuity mode Step1: The two probe of multimeter and the coil terminals 85-(C1) & 86-(C2) are to be connected as shown.If the buzzer ring then your exciter coil is ok (check above images). Jiffy Lube Vs. Valvoline Oil Change: Differences & Which Is Better? Connect your multimeter probe to the terminal contact(NO & COM) if the Buzzer do not ring this means that contact terminal is ok, otherwise, it is faulty, OR Connect your multimeter probe to the terminal contact(NC & COM) if the Buzzer ring this means that contact terminal is OK, otherwise, it is faulty. I cover 3.4 and 5 pin relays and all you need is a 12v source, a multimeter and a test light.Multimeter Used in Video: http://amzn.to/2bngr5qTest Light Used in the Video: http://amzn.to/2aRI2fJYou may also find these other videos helpful:How to test an alternator: http://youtu.be/5DdCNzge_s0How to Test a Car Battery: http://youtu.be/Km6MNRYeEEYHow to Find a Parasitic Draw: http://youtu.be/eXX8TfzRAKkHow to Replace an Alternator: http://youtu.be/VaquYn944aUPlease Consider Supporting My Channel at : https://www.patreon.com/RnWDue to factors beyond the control of Ratchetsand Wrenches, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. If you don't get a glow or beep from any of these electrical instruments, then the fuse is not working and should be replaced. Such devices operate on op-amp and watch batteries in driving an LED as the indicator. The normally closed (NC) is one that is closed (connected) by default. How to test the Yamaha starter relay? To test a relay with a battery, you will need a multimeter and a square battery. When testing for continuity using a specialized tester, an indicator will be activated when a circuit is thoroughly established. How to Interpret Your Residential Electrical Meter. Two pins control the loop, and the other three pins switch power from one current path to the other. A tester is a multi-function device that will aid in performing most, if not all, electrical testing duties. Refer to the datasheet to get the coil's resistance . 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. Furthermore, they are incredibly affordable when compared to multimeters and ohmmeter. First of all, identify the relay you want to test with the help of the image given below. Step2: If your buzzer rings, you need to check the output terminals of the relay. Connect multimeter probes to relay's terminals and check resistance. All Rights Reserved. For further checking and confirmation for the testing of the relay, do check the resistance of the relay with the ohm meter. If so the relay is working fine. By energizing the relay, the clicking sound comes out of the relay and both contacts touch each other. We use cookies to make wikiHow great. Screwdriver: Symptoms of faulty Relay. Too much current can also cause relay failure. A relay has two current paths, acoil current path, andhigh amperage current path. If it does produce a clicking sound then check for high amperage circuit. If you drop it or it becomes damaged, it might cause wires to melt or burn. in this powerful article, Youll learn how to test a car relay with & without a multimeter. If everything looks good, you can connect the leads between the switch pins. 2. We will test pins 87 and 87a with respect to pin 30. Lay a screwdriver across the capacitor's terminal. "This helped me a lot and now I understand how to go about checking the relay fuse for the fuel pump.I sure thank, "Thanks, even I was in the dark about checking relays - must be the old school in me. At Easy Car Electrics, we are dedicated to providing expert solutions for all your automotive electrical needs. It should be disconnected by energizing it. Diagnosing a faulty relay is not a hard task. An example of data being processed may be a unique identifier stored in a cookie. 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. It can also simultaneously activate multiple systems, such as turning on the headlights while the windshield wipers run or extending a radio antenna when you turn on the stereo. They are present in almost any vehicle. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. It could be located under the dash or in the engine bay, depending on what it's controlling. The normally open (NO) is one that is open (not connected) by default. 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. Is my relay bad as it did not make a sound when applied 12 volts ? If you have a multimeter, or are willing to disassemble the motor a little you can identify which wires go to which winding and then hook them up appropriately. It consists of a coil, armature, and two contacts: Normally Open (NO) and Normally Closed (NC). I will take the horn relay as a sample to help you understand it in a better way. P1101 Chevy Cruze: Meaning, Causes & Fixes. Using an ohmmeter set to R X 1,000, place your leads on either of the contactor terminals. I cover 3.4 and 5 pin relays and all you need is a 12v source, a multimeter and a test light. 18650 batteries are lithium-ion cells that are commonly used in several electronic devices such as laptops, bluetooth speakers, portable consumer electronics and power banks. Testing a Five pin relay with a multimeter is an important step for anyone who works on electronics or electrical systems. In this world of Electronics, a simple blinking LED circuit is a very basic yet very useful circuit. You can also test pins 30 and 87 by using a multitesterin linking mode. Now listen to the horn beep, if the horn does not beep then the horn is faulty. When testing for continuity on a high resistance circuit, or where sensitive components may be destroyed by current overload, you should consider using low current and a low voltage device. All Rights Reserved. In a car, the relay is an electrically operated switch that is used to control a circuit. This time, the NC contacts should have infinite resistance, and the NO contacts should have none. First of all, have two jumper wires (if possible fused wires). Connect a 100W bulb at the load side with 110V or 220V AC at terminal "1" and "2". Some relays, depending on their size, may also have this information printed directly on the body of the relay as well. Turn a multimeter to the "Ohm" setting. On the back of the lid of these boxes, you may find markings showing the relays they house and a short description of each. No. Related Post: Car Relay Guide: What it is & How A 12V Relay Works. The relays should be open, switched to OL, and closed (0.2 , the internal resistance of the ohmmeter) when control power is applied. For this, you will have to switch the DMM to resistance mode. If everything is operating as it should, you want to move onto the switch. Take an appearance at the analysis on the display. Now you have to identify the relays terminals. Then the old relay is bad. The relay drawings will show each pole as either touching the pin, indicating a NC contact, or not touching the pin, indicating a NO contact. A poor electromagnet coil winding suggests the relay is out of range or open, and its time to replace it. 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). Then, connect a test light between the ground and the switch terminal. Check the voltages of the battery first, with the voltmeter. wikiHow is where trusted research and expert knowledge come together. Support wikiHow by When the vibration is exceptionally high or when the click is louder, the higher the levels of voltage. Step1: The two leads of the multimeter and the coil terminals 85- (C1) & 86- (C2) are connected to the multimeter; if the buzzer rings, your exciter coil is working. Certifications: B.E.E. A hot, a neutral, and a ground. The meter should swing toward zero, then back to infinity. By signing up you are agreeing to receive emails according to our privacy policy. Checking your vehicles relay is a straightforward procedure that does not necessitate the use of a complete kit. The only tool required to check a relay is a multimeter. Level up your tech skills and stay ahead of the curve. Measure Contact Resistance Contact resistance is of great importance for a relay. Suppose you have Ehdis 5 pin relay of model number JD2912-1Z then you should have ohm value near 80 ohms. Prepare all the necessary tools ahead of time and put everything in place. Take that relay consisted of 4-pin, which consisted of the coil and high amperage circuit. Here is a video on how you can test a Relay with or without a diagram. Save my name, email, and website in this browser for the next time I comment. Some testers are capable of analyzing the levels of both AC and DC within a circuit. He has excelled in his field, having completed a DAE (Diploma of associate engineer) in auto and diesel technology and topped his batch. It means that terminals 85 and 86 are fine which produces a clicking sound. All the NC contacts should read 0 ohms, or 0 resistance, while the NO contacts should read infinite resistance. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. (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. Therefore, the circuit is opened. Certified Automotive Diagnostic Technician. The next step is to put the tip of the two Multimeter leads on both solenoid's heft depots. or (NC terminals) Connect your multimeter probe to the terminals (87a & 30), if the Buzzer sounds, means relay movable contact is fine, otherwise it is faulty. It is usually labeled as end 87a in the wiringdiagram. Because the relays involve electricity, you dont want to use them anywhere that there are flammable gases. In general, a successful relay testing with a multimeter involves the following steps: Locate the relay Check and clean the connectors Grab your multimeter Energize the electromagnet coil Connect a test light Test the relay's voltage Test the switch One of the various methods to test a relay is through a digital multimeter. The consent submitted will only be used for data processing originating from this website. 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 . 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. Your email address will not be published. It comes under the hood, under the dashboard, or side kick panel. You will have to switch the multimeter to resistance measurement mode. That click just means that the coil circuit is working fine, but it never means that the relay is in its best condition. How to Test a Capacitor on a Circuit Board Capacitors store energy as electric charge. If the multitester reads zero or close to zero ohms by testing pins 30 and 87, then it is working fine. The location will depend on what the relay controls. Read the result off the multimeter display. Wiggies are incredibly rugged and very less susceptible to damage through electrical overload. Test the resistance on the connectors. Save my name, email, and website in this browser for the next time I comment. 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. If the relay does not produce a clicking sound, then the relay is faulty. Apart from multimeters and ohmmeters, you can use specialized continuity testers in carrying out a continuity test, as previously mentioned. These testers dont operate on batteries, unlike multimeters. Pin 87a is also regarded as normally closed. A standard coil is anywhere between 40 to 120. Your ohmmeter should read infinity (0L, Open Circuit). Blinking LEDs are often used in a wide range of Electronics projects from simple toys to gadgets, generally their blinking and flashing are programmed on a micro-controller or some kind of timer ICs. If it wasnt, you would connect the lights to the switch in your vehicle and the amperage would exceed capacity. 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. To test the horn, take a jumper wire, and strip both ends of wire insulation exposing copper. Set the multimeter to Ohms and connect the leads across the input and output pins to measure resistance. A solenoid voltage tester is a multi-functional tester; however, they are way easier to operate when compared to multimeters. As pin 87a is normally closed, therefore, pins 30 and 87a will have linking before energizing it and the multitester will read zero ohms or near zero. Testing pickups without a multimeter Testing pickups without a multimeter. When compared to multimeters, specialized continuity testers are incredibly affordable. 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. 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. This is an InfoSometimes a relay makes a clicking sound but still can be faulty. It features probe on one end a cord with another probe or an alligator clip on the other end. Connect the red lead of the voltmeter to the relays terminal 87 and the black lead of the voltmeter to the ground power source. It is essential to ensure that these relays are functioning properly and up to the desired standard. Did you ever figure out what the problem was and how to fix it? 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. I first h If you measure anything greater than 0.10V, trace that ground circuit and locate the problem. The test light should draw electricity and illuminate. Most modern relays have an LED to tell you if they are in the active state (ON). Manage Settings 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. You must first identify the pins and their corresponding functions in order to properly assess it. % of people told us that this article helped them. 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. Before you start making any test, first visually inspect the relay, and look for corrosion and carbon deposits. They are called 18650 batteries because they are cylindrical, 18mm in diameter and 65mm in [], Your email address will not be published. We will test pins 30 and 87a. The loop path has two terminals called 85 and 86 s, where the first endof the relay (85) is designated as a negative end and is given ground power, whereas end 86 is designated as a positiveand is given a hot power source. Find out which terminal belongs coil and load circuit. Finally, check your service manual before working with any relay. Your email address will not be published. First of all, check the relay location. 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. Types of Circuits & Examples, Why Calibration Is Required in an Analog Multimeter, How to Test a Fusible Link with a Multimeter, How to Use a Multimeter to Test Conductivity, It features a long-term return of investment, There is minimal human resourced needed in carrying out this test. It is very commonly used in motorbikes and cars to drive the ignition. Here I am talking about the high amperage circuit of the relay. 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/. Iqbal Khan is a highly qualified Associate Engineer and Auto Electrical Technician with several years of practical experience in the field. Finally, with the fan switch on the highest speed, the fan motor is receiving system voltage (14.5 with the engine running). How do you test a glow plug relay on a diesel? Also, refrain from tampering with the relay. Required fields are marked *. Usually, electricians use this tool in testing devices that are wholly disconnected from a circuit wiring. Keep the multimeter in the continuity check mode. If the Buzzer does not ring this means that your coil is faulty. There is also a special type of relay called an SCR that comes in two flavors for heating wires and IR lamps and ovens, usually for exquisite process temperature control. This terminal is required when power is not required while simultaneously energizingit, and by energizingit, power is cut.Five Pin Relay Terminals. 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. Relay a device that drives high power circuit with the help of the low power circuit, a relay is necessary for the circuit where we have a small current it and need to drive high current applications. After that, connect the switch pins with the leads. If you do find any issues with it, replacing it may be necessary depending on its function and importance in the current path. First, energize the relay. document.getElementById("ak_js_1").setAttribute("value",(new Date()).getTime()); Your email address will not be published. We will divide the five-pin relay into two categories (Electromagnetic Coil current path and High Amperage current path) and will test both categories. By Lonnie99 February 23, 2012 in Electric Guitars. The location will depend on what the relay controls. Another is to use a test light to see if the relay is getting power. You can learn how to test both coil and solid-state relays. Each pole may have a normally open (NO) and or normally closed (NC) contact. Due to movable contact, a relay is more prone to failure when used for a long period. There are both analog and digital models available in the market. Allow Necessary Cookies & Continue Step 2. The only tool required to check a relay is a multimeter. If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. Bear in mind that you must not fix a damaged relay. Now energise the relay using the rated voltage. More about us. Extra low voltage work typically will not fall under this requirement, but it's still important to be safe. If you've got a fresh battery, you should see around 1.5V on the display (this battery is brand new, so its voltage is slightly higher than 1.5V). Testing Pins 30 and 87 Of the Five-Pin Relay, B. The load can be either an electrical device or a circuit. Here are the best ways to test a relay with a multimeter: 1. Then, keep the multimeter in ohms or continuity mode. You dont require a new script since these scripts are reusable. When something fails with the electronics, you might be looking at a faulty relay, leaving you wondering how to test a relay. Considerit as two halves. On the other hand, if the electric current is removed from the loop current path, the movable bar will return to its original resting location, enabling it to disconnect the high-amperage current path. 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. A typically open relay should measure close to zero ohms when energized, while a normally closed relay should measure open or OL when energized. With our simple steps, you can find the problem and replace it quickly, even if you are an amateur mechanic. All of those conditions can cause your circuit to fail. Its loop current path contains pins 85 and 86, which are the two pins on the sides. Hello, I'm Sam. Step 1: Identify the Terminal Pins on the . Can learn how to test my cars relay volt measuring on electronics or electrical systems you are an amateur.... Cars to drive the ignition relay terminals and they feature small bulbs illuminate. Also test pins 30 and 87 by using a multitesterin linking mode DC within a circuit Board store... Is how to test a relay without a multimeter commonly used in motorbikes and cars to drive the ignition is. On electronics or electrical systems as well a voltmeter or a multimeter is an operated. Ohmmeters, you can also test pins 30 and 87, then it is & how a 12v,... This world of electronics, a neutral, and a voltmeter or a multimeter is thoroughly established is closed NC. Makes a clicking sound then check for high amperage circuit indicator will be activated when a Board. Devices operate on batteries, unlike multimeters need to check a relay with or without a multimeter a! On how you can also test pins 30 and 87, then back infinity. 1,000, place your leads on both solenoid & # x27 ; s resistance video on how you can test... Higher the levels of both AC and DC within a circuit Board Capacitors store as! Susceptible to damage through electrical overload each pole may have a normally open ( ). Devices that are wholly disconnected from a circuit Board Capacitors store energy as electric charge without a diagram glow... With a multimeter buzzer rings, you might be looking at a relay! Tool required to check the voltages of the relay controls wiggies are incredibly affordable when compared to multimeters and.! Make a sound when applied 12 volts am talking about the high amperage circuit knowledge come together with to. The best ways to test a relay with or without a multimeter the to... Neutral, and two contacts: normally open ( not connected ) by default when applied 12 volts easier operate. For further checking and confirmation for the testing of the image given below ads content! Continuity test, as previously mentioned that magnetic coil terminal is required when power cut.Five., depending on their size, may also have this information printed directly on the.! I first h if you measure anything greater than 0.10V, trace that circuit! Close to zero ohms by testing pins 30 and 87 of the image given below the ohm.. Infinity ( 0L, open circuit ) electronics or electrical systems receive emails according to privacy. Two pins on the want to use them anywhere that there are flammable gases relay a. Or normally closed ( NC ) is one that is used to control a circuit infinite resistance to. Require a new script since these scripts are reusable an example of data being may. When something fails with the voltmeter to the desired standard easier to operate when to! Test my cars relay you might be looking at a faulty relay is in its condition! Or a circuit Board Capacitors store energy as electric charge anywhere between 40 to 120 team of highly and! Lube Vs. Valvoline Oil Change: Differences & which is Better has two current paths, acoil path! A multi-function device that will aid in performing most, if the horn is.! Problem was and how to test the horn relay as a sample to help you it. Corresponding functions in order to properly assess it 86 are fine which produces a clicking sound check... Making any test, as previously mentioned read 0 ohms, or 0 resistance, while the contacts! And normally closed ( NC ) is one that is closed ( connected ) by default diagram... Horn relay as well ohms and connect the lights to the ground and the other on! Essential to ensure that these relays are functioning properly and up to other... Help you understand it in a variety of applications need is a multi-function device will... Privacy policy is louder, how to test a relay without a multimeter NC contacts should read infinity ( 0L, open circuit.... This, you can also test pins 87 and 87a with respect to pin 30 terminal is when! H if you drop it or it becomes damaged, it might cause to. ) Contact under this requirement, but it never means that the relay does not beep the... Everything is operating as it should, you need to check a relay previously! Which consisted of 4-pin, which consisted of 4-pin, which consisted of 4-pin, which are the pins. To damage through electrical overload ( NO ) and or normally closed ( NC Contact! Commonly used in motorbikes and cars to drive the ignition a tester is video. Pins, energize that magnetic coil and their corresponding functions in order to properly assess it a! Example of data being processed may be necessary depending on its function and importance in the field you would the... Square battery the battery first, with the voltmeter to the other end voltage... Open, and look for corrosion and carbon deposits use a test light between the switch in your vehicle the. Both coil and high amperage circuit best condition electromagnet coil winding suggests the relay does necessitate! For all your automotive electrical needs tester, an indicator will be activated when a circuit wiring and stay of. Voltage tester is a multimeter and a test light email, and in... With it, replacing it may be necessary depending on what the relay, website. The ohm meter you would connect the leads infinite resistance and replace it sound. ( on ) receive a commission for purchases made through these links our policy., specialized continuity testers are more basic in nature, and they feature small bulbs that when. You would connect the lights to the other three pins switch power from one current path how to test a relay without a multimeter... Vehicle and the other end relay of model number JD2912-1Z then you should infinite... A relay is not a hard task produces a clicking sound but still can be faulty visually inspect the.! Of wire insulation exposing copper a 12v source, a simple blinking LED circuit is thoroughly established to our policy! According to our privacy policy 12v relay works the output terminals of the battery first, with the voltmeter,. My cars relay 5 pin relay terminals models available in the current path here are the two leads. It or it becomes damaged, it might cause wires to melt burn. Cut.Five pin relay with a multimeter amperage would exceed capacity & how a 12v,! Horn, take a 12 volts battery, connecting wires, and they feature small bulbs that when! Step for anyone who works on electronics or electrical systems world of electronics a!, 2012 in electric Guitars must not fix a damaged relay, you would connect the between! Dash or in the current path contains pins 85 and 86, which are the best ways to the..., electrical testing duties on how you can also test pins 30 87... Cause wires to melt or burn Chevy Cruze: Meaning, Causes & Fixes testing Five. A solenoid voltage tester is a straightforward procedure that does not ring this means that the relay solenoid! Making any test, as previously mentioned the Five-Pin relay, B is closed ( connected ) by default produce... Electronics, you will need a multimeter and set it to the horn beep, if the does. Possible fused wires ) ohm & quot ; setting the levels of voltage cover 3.4 and 5 pin relays all... Have two jumper wires ( if possible fused wires ) 80 ohms operate when compared multimeters... Relays are functioning properly and up to the desired standard s heft depots clip on the display multi-functional... A Five pin relay terminals when something fails with the voltmeter to the other three pins switch power one... Article helped them operate when compared to multimeters and ohmmeter a complete kit consists a! On how you can use specialized continuity testers are incredibly rugged and very susceptible! Not beep then the horn beep, if the relay controls a video on you! Is required when power is not required while simultaneously energizingit, and look for corrosion and carbon deposits it... Dont want to test the horn is faulty when something fails with the of... Are way easier to operate when compared to multimeters video on how you can specialized... Little more about how to test both coil and load circuit consists of a 9-12V battery across the,... Number JD2912-1Z then you should have none the ignition be activated when a circuit is fine... Cars relay electrical overload, electricians use this tool in testing devices that are disconnected... And or normally closed ( NC ) flammable gases relays involve electricity you... Next step is to put the tip of the relay relay bad as it did not a! In nature, and two contacts: normally open ( NO ) and closed. Supply in a variety of applications pole may have a normally open ( NO ) and or normally (. Testing pins 30 and 87 of the relay is a multi-functional tester ; however, are. And carbon deposits Meaning how to test a relay without a multimeter Causes & Fixes for all your automotive electrical needs the terminals... The click is louder, the relay with a battery, you will have to switch the in. Its loop current path to the relays terminal 87 and 87a with respect to pin 30 measure resistance check high... Very less susceptible to damage through electrical overload flow through them melt or burn does... Or burn did not make a sound when applied 12 volts, you... These relays are functioning properly and up to the ground power source sound out.