This blog will give you a solution to checking 5-pin relay with a multimeter in simple steps. If you are facing a failed or malfunctioning ignition system of your car or truck, that’s may be due to a faulty starter relay. If an industrial motor’s mcc panel or other circuits failed in performing their basic functionality, the first step in the troubleshooting should be to test their relays.
Relay is a type of device which is now present in almost all types of electronic systems. Whether it’s a vehicle circuit, industrial motors control system, or any other electric installation you will find relays everywhere.
How to test a 5 pin relay with a Multimeter
Relays are actually electronic switching devices that are used to control the power supply to some circuit or machinery. For dealing with heavy load systems we can’t rely only on direct power supplies. But we can control this with help of a controlling system that can delay, switch or stop the power flow.
For checking the malfunctioning 5-pin relay, follow these simple steps given below.
Initial steps to check 5 pin relay
- Normally every relay has three basic terminals other than its power terminal which are normally open(NO), normally closed (NC) and common.
- First of all check relay physically, it should not have any worn, spark, or debris signs. Otherwise replacing it would be a better option.
- Now turn on the power supply to relay, it may be 12v dc or 220/120v ac and verify it with help of multimeter by testing voltage value coming to relay. By this, we are confirmed now that there is no power issue with relay.
Testing terminals of 5 pin relay
- Switch your multimeter to the resistance testing point and set it to the highest ohms range.
- Now place one probe of meter on COM point and other on normally closed or NC point of relay. If this terminal of relay is working well then it should give a reading of zero or close to zero ohms.
- Now connect one probe of automotive meter with COM and other with normally open or NO terminal.
- If the meter is giving a value of mili ohms or even higher ohm value that means this point of relay is working accurately. If the results are near zero ohms then this is definitely a faulty relay and you have to replace it immediately.
- Till now, we have checked NO and NC terminals of relay, now if these points have no problem we should check the coil of relay.
- Connect multimeter probes to relay’s terminals and check resistance. To verify the rated value of resistance for relay coil, read manual or guidebook of that relay.
- Suppose you have Ehdis 5 pin relay of model number JD2912-1Z then you should have ohm value near 80 ohms. If meter result is noticeably higher or lower than this range, it’s a sign that the relay coil is not working well.
Symptoms of a faulty Relay
There are several symptoms and signs of a failed or malfunctioning relay. In cars and other vehicles one may see an error or warning sign on screen, delays in starting of engine, some clicking sounds by relay, corrosion and dirt around the relay.
In industrial motors which are powered through relays, we can experience same issues like no power to motor even when electricians have powered on the main mcc switch of motor. Or motor isn’t stopped when operator give command to stop that motor through plc (programmable logic control) system.
Sometimes due to some surge or heating issue relay contacts can melt and weld together, in that case, relay can cause serious damage due to its reverse operation. Reverse operation means when you turned off the car engine, the faulty relay with joined terminals will still give power to the starter and other circuits if not replaced.
We tried our best to give a brief process on how to test 5 pin relay with a multimeter on your own. Primary thing is to verify the accurate working of relay terminals. We will advise you to don’t play with circuits if you are not trained well to do so. Otherwise, you should call any electrical agency or an automotive electrician for conducting this test.
For more knowledge watch the video below by “ratchets and wrenches”.
Leo Maxwell is basically an Electrical engineer and hobby tech writer, having 13 years of experience in the electronics and instrumentation industry. He has hands on experience working in various fields like Powerhouses, solar, automotive, and FMCG.
During his career, he has used many power tools and meters in electrical projects. Now his aim is to explain tools and troubleshooting in easy guides to help people. Other then it, leo loves traveling, reading books and DIY tasks.