How to Test a 3 Pin Flasher Relay with a Multimeter

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Did you know that an LED flasher module is a crucial device for your car? For example, you can use the flasher on the turn signal or indicators of your car. The module is composed of various parts that we will talk about in this guide. 

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How to Use a Digital Multimeter

By the end of this article, you will also understand how to test a 3-pin flasher relay with the help of a digital multimeter. If you’re ready to find out more, let’s get started! 

What is a Flasher Relay? 

Did you know that a flasher relay is created to control the flash rate of a vehicle directional indicator? That is accomplished by offering regular interruption of the electric current within the indicator circuit. You will find three types of flasher units: thermal, electronic, and electro-mechanical. 

Typically, a 3-pin flasher relay functions based on the idea of electromechanics. The power turn and hazard signals on many vehicles were created in the 1930s. In the past, these signal systems transformed from mechanisms and relays to solid-state apparatuses. Keep in mind that most flasher relays today have a visible and audible output when connected as manufactured. 

Top 3 Indicators You Need to Replace Your Flasher Relay 

Normally, a malfunctioning flasher relay creates several indications that might inform you that something is wrong. Those signs are the following:

  • Other lights are not properly working – There are instances when other lights like the brake lights, running lights, or headlights may also not work properly together with your flasher relay. It might be because such lights connect through or with your hazards in other vehicles. Often, it results in other lights not working, too, except the turn signals are incorrect. 
  • The flasher relay keeps on lighting – A flasher relay that remains on is another concern indicating you have a bad unit. One of the common causes for this problem is a problem with electrical components. It will help if you check your vehicle on a regular basis. 
  • It won’t function anymore – A broken flasher is another common sign of a bad flasher relay. That could cause the lights not to function anymore, especially when you press the hazard light button. This concern might not result in severe engine performance problems, but it’s risky if your flasher relays are not working anymore. 

How Do You Test a 3-Pin Flasher Relay?

One of the best ways you can test your 3-pin flasher relay is with a digital multimeter. This device is one of the most versatile items you can use for any electrical purposes you may have. 

Remember that a flasher relay controls the operation of hazard flashers and turn signals on most motorcycles and cars. When a flash relay goes bad, the hazard lights and turn signals might glow dimly, whereas the flasher itself will:

  • produce a buzzing noise
  • not blink at all
  • blink too fast
  • pulse without turning off completely

Does your car show any of such signs? Then testing your 3-pin flasher relay is of utmost importance in determining the issue. Don’t forget that flashers are often susceptible to fail and depend on a particular load to work efficiently. 

Here are the steps you need to do when testing your 3-pin flasher relay with a digital multimeter.

Step 1. For the first step, make sure you determine the terminals. Flasher terminals often have a power source terminal, designated as B for battery and L for load terminal, and P for panel.

The circuit diagram is written on the case to help you identify those. If they aren’t labeled, you can use a digital multimeter to identify which prong is open at rest. 

Step 2. Click your test probe between the P terminal and the negative test lead to the battery.

Step 3. Attach the B terminal to the battery’s positive terminal using the test wire with the same length of stripped ends, along with one clip on every end. 

Step 4. Cover the long-stripped end of the second piece of wire around the test bulb’s base cylinder. Make sure you secure it with a twist and attach the short-stripped end to the L prong using the third clip. 

Step 5. Attach the center connector of your test bulb to the battery. At this moment, your unit should begin flashing, causing both the load bulb and the test light to blink. Moreover, the action will be twice as quick as normal, as the test bulb signifies half the average load on the relay.

Do your bulb and the test light blink at normal intervals. Then it indicates your relay is working perfectly fine. If not, it means your unit should be replaced right away. 

Do your turn signals still do not work after you have changed your bad flasher relay and notice the bulbs are already functioning properly? Then you may need to check the electricity. 

Often, the one thing you should do is to check the connections. It will help if you access the back of the flasher relay housings so as to change the bulbs. Unplug the connection in that location between the taillights, the car’s electrical system, and the front turn signals. You can then plug them in one at a time. In other situations, doing this might help you deal with the issue. 

Final Thoughts

As you can see, having a flasher relay on your car should be the best thing you need to consider. As seen from this guide, testing a 3-pin flasher relay using a digital multimeter is not a huge deal. You only need to assemble the needed materials and test the device on your vehicle. 

On top of that, a flasher relay is simple to identify in case of any failure of functioning. So, what about you? Are you ready to test your flasher relay with the steps we mentioned as your guide? 

Feel free to visit our website again if you want to test other equipment or devices with your digital multimeter. We hope you find this post informative and educational.

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