Use a digital multimeter dmm to test the resistance between each pole of the relay and the corresponding nc and no contacts for that pole. Httpsamznto2kplxwf testing a relay is not as complicated as people think.
How To Test A Relay
How to test a 5 pin relay with multimeter. In the above video purkeys national truck fleet representative larry rambeaux demonstrates how to test resistance on a 5 pin relay using an ohmmeter. In the datasheet you will also get the tolerance value of the coil. For example if the resistance is 320ω and the tolerance value is 10 then we should get resistance values somewhere between 288ω to 352ω. The ohmmeter measures resistance in ohms ω. When the two pins that control the coil activates normally closed pins will switch to normally open terminals. Test the de energized condition of the relay contacts.
The polarity of probes on terminals doesnt matter because we are finding resistance. One of the more frequently used functions of the multimeter is the ohmmeter. This is the easiest way to do it out of the car and the only way it should be done. This video shows you how an automotive relay works and how you can test it using an digital multimeter. All nc contacts should read 0 ohms to the corresponding pole. Below is the test that should be conducted on a 5 pin relay.
You will find the resistance of the relay coil. One thing commonly tested on heavy duty trucks is the 5 pin relay. A 5 pin relay has two pins that control the coil and the rest three pins switch power between circuits. Many technicians are quick to replace this part without properly testing it first. The first step is to test the coil of relay refer to the datasheet to get the coils resistance. How to test a 3 4 or 5 pin relay with or without a diagram duration.
You will need a 12v power supply or car battery and multimeter voltmeter. To check the coils resistance with a multimeter take a multimeter and put it on the ohmmeter setting then connect the multimeter probes on any two terminals of relays coil. The three pins have both no normally open and nc normally closed connection pins. To test it technicians need to know what the resistance should be. All no contacts should read infinite resistance to the corresponding pole. How to use a multimeter for beginners how to measure voltage resistance continuity and amps duration.
How to test relay any relay voltmeter.