Test Circuit Board Relay

Relay test 2 listen for a click supply 12 volts power to 86 ground to pin 85 you will hear 87 to 87a closing click.

Test circuit board relay.

The main reason for testing a relay is to find whether it is a good or defective one. This article shows you how to test a relay. Automotive relay tester diagnostic test and measurement tools code readers and scan tools test relay open and close with led light black and red 4 3 out of 5 stars 38 21 99 21. The first step is to test the coil of relay refer to the datasheet to get the coil s resistance.

Test the de energized condition of the relay contacts. The simplest way of finding this is to use a multimeter with an ohmmeter setting and then measuring the resistance values by checking its terminals. Relay test 1 set meter to 200 ohms test for resistance between 85 and 86 circuit with coil acceptable range 50 to 120 ohms example 70 ohms is good below 50 or above 120 ohms relays is bad. The set of contacts that are open when the relay is not energized are called normally open n o contacts and the set of contacts that are closed when the relay is not energized are called normally closed n c contacts.

A 4 terminal relay is used so a low power circuit may engage a high power circuit without risk of damage to the low power control circuit. All nc contacts should read 0 ohms to the corresponding pole. Video tutorial on how to troubleshoot and test a relay on a 12 volt application. How to test relay any relay voltmeter.

In this article we will show what resistance readings you should get when you measure various points of a relay. A relay will usually have a coil pole terminal and a set of contacts. Relays are used for numerous applications on your vehicle or small engines s. The purpose of testing a relay is to find whether it is good or bad.

Use these tips to learn how to test a 4 terminal relay. 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. For example a low power circuit in a car that commands the high power headlights to come on would send the command through a 4 terminal relay. And one of the best ways to do this is to use a multimeter with an ohmmeter setting and then measuring the resistance values.

All no contacts should read infinite resistance to the corresponding pole.