ATV Buzzing When Trying to Start

If your ATV or side by side is making a buzzing sound when you try to start it, it’s often 3 things.

  • A weak or dead battery.
  • Bad battery connections.
  • A bad starter relay.

When Does The Buzzing Happen?

Before we go too deep, we need to figure out when the buzzing happens.

If the buzzing happens when you give the ATV power, as in putting the key on and before you hit the start button, that is your fuel pump.

The fuel pump will make a humming noise and can be louder if there is no gas in the tank. If the fuel pump is really loud, then that is a sign it’s going bad, and it needs to be replaced.

If the buzzing comes after you hit the start button or turn the key to the start position, that is either the battery, battery cables, or starter relay.

Bad or Dead Battery

9/10 times I find it’s either a bad or dead battery that causes an ATV not to start and create a buzzing sound.

Many guys will put their ATVs up for the season and not touch them for months which kills batteries. You need to keep a smart charger or solar charger on your ATV if you’re not going to ride it for months.

The buzzing or the clicking sound you hear comes from the starter relay flipping back and forth very fast. Since there is not enough power in the battery, the relay gets stuck in the middle as there is not enough juice to fully send it over.

You’ll need to load test the battery. Some guys check the voltage with a multimeter across the battery to see the voltage drop but, to be honest, this is not the best way to test a bad battery.

The best way to test a battery is with a load tester*. It’s just good to have around the home as it can test any 12-volt battery, even the one in your car. Hook the battery up to a load tester and press the load button to see how much it drops.

If the battery has been sitting for months, you can try to charge it, and many of them still recover. If the battery is over 3 years old, I would go ahead and replace it as it’s getting near the end of its life anyway.

The Battery Is Fine

If the battery is fine, recheck it.

No, seriously, most of the time, it’s almost always the battery causing your buzzing.

I’ve even seen new batteries give issues, mainly because the guys at the store did not charge them or were simply defective.

I’ve even tried jumping the battery from a jump pack, thinking it just needed a boost, but that is not always good enough. I ended up putting a new battery in, and everything was fine, so you can’t always trust jump packs either.

Batteries will play tricks on you; never trust the voltage reading on them.

The voltage readings mean nothing; we need amps when cranking a battery; this is why I don’t like telling people to use multimeters and instead tell them to use load testers.

If you tried everything else, get a second opinion on the battery. Take it to the local autoparts store and have them load test it; many do it for free.

Loose Cables

Loose cables can also cause an ATV to make a buzzing sound.

I find it’s most often the battery cables themselves either from coming loose over time or the last guy didn’t tighten them down all the way.

I see far too many guys use screwdrivers to tighten battery cables. The battery bolt does have a Phillips head on it, but that is only to start the threads. You need to use a wrench or a socket to snug it, don’t over tighten it as it bolts to lead, which is soft.

You also need to be careful when using a wrench as it can be tight, and you don’t want to touch the metal wrench to the other battery terminal or any metal in the ATV. I’ve got a scar on my finger learning this the stupid way, but to be fair, 2008 Renegades have a horrible battery location.

I’ve also seen loose battery cables cause all kinds of issues like check engine lights or the ATV shutting off.

Don’t forget to check other cables like the ones going to the starter relay. These cables can get loose over time, too, and need to be tight, or you’ll have issues.

A Bad Starter Relay

A starter relay, also called a starter solenoid, can cause buzzing sounds from your ATV.

In fact, the buzzing sounds you hear come from it not making proper contact.

Usually, it’s a bad starter relay when you hear one click.

It’s a bad or weak battery when you hear multiple clicks or a buzzing sound.

But there are times that a starter relay will still make a buzzing sound when it’s gone bad. You’ll know this when the battery passes the load test, and the cables are tight.

Starter relays take a lot of abuse every time you start your engine. This is because they take the blunt force of the full battery, and over time the connectors inside can weld themselves closed or melt themselves.

Starter relays should be replaced when you think one is going bad. It’s often easy to get to on most ATVs, and it’s almost always located near the battery itself.

Other Problems

If nothing above fixed the problem, there are still a few things to try.

Check the key and start button to ensure no water got in or that the connectors are still fine. Water on the contacts can cause all kinds of random problems when trying to start your ATV.

Make sure the kill switch is good and not damaged either.

Check for loose wires or other connections especially going to black boxes. A damaged wire or a loose connector going to the computer or other components like the rectifier can cause all kinds of problems. Electrical problems are the worst as you sometimes feel like you’re chasing a ghost.

Another possible reason for the buzzing is the starter motor’s Bendix is broken.

Can You Jump The ATV Battery From Your Truck?

The next usual question I get from someone who says their ATV is buzzing and want to jump-start it, is if it’s okay to do so from their truck?

You should NOT jump-start your ATV from your truck.

When your truck is on, its charging system can overpower your ATVs electronics and fry it. You can try doing it with the truck off, but I still don’t recommend it.

You need to use a jump box or another ATV battery.

If you want something that will blow your mind, you can get a super-capacitor jump-starter* that charges off your dead battery. Yes, I know it sounds crazy, but it works, as shown in this video. I keep one around in my truck, but I take it with me when I go on long rides with my ATV.