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Can a Bad Alternator Cause a Misfire? (Read This First!)

An alternator is basically a machine that powers up the electrical components of most of the modern vehicles by transforming mechanical power into electrical power.

Since an alternator is greatly responsible for generating power for electrical components of a vehicle, a bad alternator surely would make you think whether or not it is going to be caused a misfire. 

Thence, let’s read through the explained segments ahead without making further ado. 

Can A Bad Alternator Cause A Misfire?

A bad alternator can cause a misfire. Most modern vehicles need a stable electrical power of a particular voltage to work. So when an alternator failure occurs, the supply of the steady electrical power drops down and it causes misfire while showing signs of several electrical system malfunctioning.

A bad alternator certainly can be responsible for causing a misfire that includes several electric systems malfunctioning. 

An alternator converts mechanical power to electrical power to recharge the vehicle’s battery and power up many electrical systems while the engine is functioning.

So, when an alternator failure occurs, the alternator can’t convert mechanical power into electrical power either for recharging the battery or power up the electrical systems. 

And then, a misfire happens that includes a cylinder misfire which means there will be difficulty in starting the engine, the engine will make odd sounds, and the engine will stall frequently. Not only a cylinder misfire but a random misfire also can be caused by a bad alternator.

And if a random misfire happens, the issue will not stay between 1-2 cylinders, rather in a random means it will jump from 1 cylinder to other ones 

Other misfire symptoms like slow rolling up of the windows, radio being turned off, drained out battery, etc. also are caused by a bad alternator. 

How Does A Bad Alternator Cause A Misfire?

Due to continuous overuse or aging, a bad alternator problem occurs. And when an alternator failure occurs, it causes misfire by not being able to convert mechanical power into electrical power in a steady manner to power the vehicle up for functioning properly.

And this misfire caused by a bad alternator comes up one or more electrical system malfunctioning such as rough idling, change in the engine’s sound, sluggish acceleration, appearing of battery warning light, and more. 

So in other words can be said that, by causing one or several electrical malfunctioning, a bad alternator causes a misfire. 

What Are The Signs Of  A Bad Alternator? 

An alternator is nothing but a machine, so it can go bad. Thus, if you are undergoing one or several of these following signs listed below, just comprehend that it’s a bad alternator problem. 

Drained Out Battery:

A bad alternator surely can cause a drained out battery problem, as that bad alternator will not be able to recharge the battery sufficiently while the vehicle’s engine is operating. Therefore, the charge will be drained out sooner than usual. 

Slow Or Malfunctioning Electrical Systems: 

As a bad alternator can’t power up a vehicle’s electrical components well, it often can result in malfunctioned electrical systems.

Signs such as the windows are going up or down slowly, the power seat is malfunctioning, or the radio has turned off suddenly on its own, etc. all are the signs of a bad alternator. 

Trouble Starting Or Frequent Stalling: 

If you are encountering trouble starting the engine (means hearing a ticking rather than a purring sound after turning the key into the ignition), it simply means the alternator has gone bad.

Moreover, while driving if the vehicle is stalling oftentimes, it can indicate a bad alternator problem, as spark plugs aren’t getting sufficient electrical power.

Odd Sounds: 

 If the car is making odd sounds such as growling or whining and the sounds are coming out from underneath the hood, it manifests a bad alternator problem. 

Dim Or Overly Bright Lights: 

When an alternator failure occurs, it provides an unsteady voltage to the electrical accessories, therefore, the vehicle’s headlights light up as either too bright or too dim. Sometimes, flickering lights or else lights turning dim from bright erratically is also a sign of a bad alternator. 

Battery Warming Light: 

The popping up of the battery warning light is an obvious sign that indicates a bad alternator problem. If you notice the red-colored battery icon staying red or “Check Engine/ ALT” is appearing, it means alternator failure. 

What Makes An Alternator Go Bad?

The maximum time an alternator goes bad when its usual lifespan (about 5-8 years) comes to an end, or else if you have improperly used or maintained the alternator. 

However, apart from these two main reasons, fluid leaking can also cause an alternator failure. It happens when engine oil or else power fluid goes inside the alternator and causes malfunctioning. 

Also, If you waste time idling while keeping the vehicle’s (such as car) accessories on use, it excessively stresses out the alternator which directs to wear and tear more. 

Besides, as the alternator is placed closer to the bottom of the vehicle’s/car’s engine, possibly it can be exposed to water and salt intrusion as both of them can get inside the alternator and make it go bad. 

How Often Do Alternators Go Bad?

As long as your driving habits are under control and the alternator is maintained well, the alternator will typically go bad after 7 to 10 years.

An alternator comes with an average lifespan of 7 to 10 year’s which typically means that it will last somewhere between 80,000-150,000 miles. Thereby, there aren’t much chances that it will go bad anytime soon in that period.

However, some mechanics claimed that alternators of some vehicles may go bad just after 50,000-60,000 miles.

And it happens because of the factors like how you are driving your vehicle, where and in what type of condition the vehicle is driven, and how many electric systems are being wielded in the vehicle. 

What Problem Does A Bad Alternator Cause? 

The problems that a bad alternator cause are listed below.

  • Stalled engine 
  • Broken or loose connection
  • Difficulty in starting 
  • Stalled engine 
  • Growling or whining noise 
  • Flickering or dim lights 
  • Electrical system malfunctioning  

Will A Car Start And Run With A Bad Alternator?

Technically a car can start and run with a bad alternator but the car will run for a very short period with a bad alternator.

It’s because the alternator is responsible for charging the battery while the car’s engine is functioning, but since a bad alternator can’t charge the battery, the battery gets depleted and the car just fails to run anymore.

How Long Will A Car Run With A Bad Alternator?

A car will run with a bad alternator for only about 5-30 minutes, as the battery will drain out soon. However, it totally relies on the power of the battery, if the car’s battery is fully charged, you may even run the car for up to 2 hours too. 

How To Fix A Bad Alternator?

In this section, a step-by-step guide has been included that will help you fix a bad alternator on your own. 

Get The Right Tool Kit: 

According to the model of your vehicle’s alternator, get the right alternator fixing tool kit and a brush before you start the fixing procedure.

Disconnect The Vehicle’s Battery: 

For your safety purposes, detach the positive (+ve) from the vehicle’s battery so that it can’t make any slight fireworks. 

Remove The Alternator: 

Google first for getting details about the making and model of the vehicle. Then from the back of the alternator, release the wire harness. After that unbolt both the short and long pin bolt that are holding the alternator at its place. 

Remove The Rear Cover On The Alternator: 

After removing the alternator, take out that plastic cover that alternators have on their rear side. There you will find 2 bolts that need to be discarded before removing this plastic cover. 

Remove Old Regulator And Brushes, Fit New Kit: 

Here, first take out the aged brushes and the aged regulator and while taking out the brushes. Then put in a new regulator and from that supplier repairing kit, note the wiring instructions.

After that fit new brushes, connect the wiring again as well as fit the bolts, and lastly tighten them but don’t overtighten them. 

Refit Rear Plastic Cover And The Alternator: 

Lastly, fit the rear plastic cover on the alternator again and put the alternator into the vehicle again but ensure that fan belt is tight enough. 

After fixing the alternator, run a test to check if it’s fixed and working well or not. 

Final Thoughts 

Misfire with several malfunctioned electrical system symptoms indeed can be caused by a bad alternator as a bad alternator would not be able to charge the battery with a constant voltage of electric power to run. Also, will not be able to power up the electrical systems to function properly.