What Does it Mean When a Relay is Buzzing?

5 mins read

Last Updated on September 16, 2022

Relays can produce a buzzing sound when they’re energized. This problem can be caused by wear on the surfaces that contact the relay. To solve the problem, clean or dress the surfaces that come into contact with the relay during its energized state. If these methods don’t solve the problem, try replacing the relay’s coil. In addition, if the noise persists, try resetting the relay to the default state.


Symptoms of a relay buzzing may indicate that the switch that controls it is faulty. The switch can be replaced or you may need to replace the relay. A buzzing relay may be due to a momentary switch. However, if the switch is still working, you may not need to replace it. Symptoms of a relay buzzing may also indicate that you should replace the relay itself.

To identify the cause of relay buzzing, you must first identify the voltage source. A DC relay has a magnetic core and is wound with wire. Sometimes, it contains a back biased diode. The amount of wire wound into a relay differs from one model to another, and the difference in turns causes a magnetostrictive effect. For instance, a 12V relay may have ten times more turns than a 120V one. A 170V relay can saturate its core 120 times per second.


A loud buzzing sound can be a sign that a relay may need to be replaced. One easy fix is to adjust the coil and switch blade tensions. Then, the relay should stop buzzing. If the buzzing noise persists, the problem may be due to a worn or deformed frame. In such cases, you can replace the switch. However, it is important to be cautious when making any adjustments to the frame and coil as these can affect the relay’s operation.

Relays have a magnetic core and are wound on wire. This wire may have varying numbers of turns, and this may create a magnetostrictive effect. Relays with more turns tend to buzz more than ones with less, which can result in a noisy operation. The number of turns also differs from model to model. Relays with 12V have about ten times more wire wound than a relay with a 120V core, while a relay with 170V can have up to 120 turns.


The first fix is to check the wiring and ensure the relay is not tangled. If the wiring is undersized, you should use a separate wire between the start-relay and the controller. Some techs suggest avoiding sharing the solenoid switch wire with the relay. Another cause of relay buzzing is dirty contactor points or coils. In addition to the dirty contacts, the relay may have a loose connection to the ground.

A bad switch or a low-voltage relay could be the culprit for a buzzing sound. You may need to replace the switch or replace the relay, if the buzzing is accompanied by a loud noise. However, if you’re unsure of whether the buzzing sound is a sign of a bad relay, you can call HomeX’s virtual experts for free assessment.


Sometimes the problem with a relay is simple and can be solved at home. The buzzing noise can occur because of a momentary switch that is keeping the coil energized. To solve the issue, try replacing the switch. However, if the problem persists, you can consider replacing the relay. Contact a HomeX virtual expert for a free evaluation. In some cases, a simple relay replacement is all that is necessary to get the relay to work as it should.

Depending on the cause of the buzzing sound, the relay may be damaged or faulty. In this case, it’s a good idea to replace the relay. The MSD switch works by leaking a small amount of current to the ground. This leakage causes the relay to cycle and close, creating the buzzing sound. In rare cases, the problem can be caused by a faulty ECM or an improperly installed relay.

About The Author

Orochi Konya is a student of the web. He has been dabbling in it since he was young, and has become an expert in his own right. He loves all things digital, from making websites to programming to social media. In his spare time, Orochi enjoys indulging in his other passion: music. He loves listening to all kinds of music and often spends hours creating playlists on Spotify. He also enjoys drawing manga and watching anime in his free time. Orochi is a friendly pop-culture guru who is always happy to chat about the latest trends in both Japan and the U.S.