Blog Car Care Advice Can You Drive With a Bad Alternator + What Are the Risks?
Car Care Advice

Can You Drive With a Bad Alternator + What Are the Risks?

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Ever wondered how far can you drive with a bad alternator?  
Well, not too far.

Your alternator is the silent hero that converts mechanical energy into electrical energy to power your car. If it goes bad, you may face a dead car battery, a lit battery light, or strange noises. 

Read on to find out if you can drive with a failed alternator, why you shouldn’t, signs of a failing alternator, and more. 

This Article Contains:

How Long Can You Drive with a Bad Alternator?

The distance you can cover with a faulty alternator depends on your car’s battery, engine condition, and electronic features. 

If your alternator is nearly worn out, you can only drive for a few miles before the battery dies or other electric problems arise. This is particularly true in feature-rich, modern vehicles that need more electrical energy.

However, if you have a fully charged battery in good condition, it can last up to 30 minutes even if you have an alternator problem — especially in older vehicles with fewer features. 

Wondering what happens when you drive with alternator trouble?

4 Common Risks of Driving With a Bad Alternator

Some issues you could face when driving with a malfunctioning alternator include:

  1. If your alternator isn’t working properly, it might not charge the car battery enough to start your car. This could potentially leave you waiting for a tow.   
  1. If the alternator and voltage regulator are faulty, they can overcharge a good battery and cause damage. 
  1. If you have electric power steering, an alternator issue can make it more difficult to control your car. This is risky, especially at highway speeds or when making turns.
  1. Driving with a failed alternator can also damage other vital electrical components, such as the water pump, power steering, and fuel pump.

Next, let’s explore the signs of a failing alternator.

5 Telltale Signs of a Bad Alternator 

Notice dimming headlights or a battery warning light
Might be your alternator giving out distress signs.

Here are some more bad alternator symptoms you should look out for:

  1. Dead battery: The malfunctioning alternator won’t be able to charge your battery properly, resulting in a dead or bad battery
  1. A lit dashboard light: When an alternator starts failing, it provides inconsistent voltage to your vehicle’s electrical system. This can trigger the battery warning light and, in some cases, the check engine light
  1. Slow or malfunctioning accessories: As a failed alternator can’t supply enough power to your car’s electrical system, it’ll slow down your electronic accessories. For instance, you may have slow power windows or dimming headlights in modern vehicles.
  1. Strange noises from under the hood: A rubbing, grinding, or squealing noise under the hood may come from a bad alternator bearing or other internal parts.
  1. Smell of burning rubber: As the alternator belt is usually under friction and near the hot engine, it may wear out and smell like burning rubber. You may also get a similar smell from an overworked alternator or if it has frayed wires. 

But what causes these alternator problems?
Delve into some of these causes next.

8 Typical Causes of a Bad Alternator

Here are the common culprits behind an alternator issue:

  1. Friction due to wear: High-speed rotation in an alternator can wear out small, critical parts like bearings, increasing resistance and strain on the system. That’s why it’s important to replace these small components along with big parts like its rotor.
  1. Electrical power overload: Adding extra electronic features like speakers can overload the car’s alternator since they demand more electrical power. Also, the fuses in an alternator can blow out over time or due to power surges, leading to alternator failure.
  1. Wiring issues: If the car alternator wires get damaged or wear out, it can lead to alternator failure and prevent the car’s battery from charging.
  1. Damaged alternator belt: Rubber alternator belts can lose elasticity and break from constant stress. This can also affect other essential features like the water pump, air conditioner, and power steering.
  1. Leaking fluids: Oil, coolant, or power steering fluid leaks near the engine can seep into the car alternator and damage crucial parts like bearings or the diode plate.
  1. Damaged voltage regulator: A faulty voltage regulator can make the alternator overcharge or undercharge the battery, reducing its performance. Plus, continuous overcharging can strain and prematurely wear out the alternator.
  1. Salt and water corrosion: Your alternator can corrode faster in regions where road salt and precipitation are common. That’s because constant exposure to salt, water, and humidity damages the alternator’s internal parts.
  1. Faulty Electronic Control Unit (ECU): Modern vehicles have computer systems like the ECU that control almost every part, including the alternator. Even a minor glitch can stop a new alternator from charging your battery or activate the battery warning light.

So what if you’re stuck with a bad alternator before you can get a replacement? 

4 Emergency Solutions for a Bad Alternator

You can try these tips to keep your car running until you replace a dying alternator:

  1. Limit electrical usage: Reduce the load on the alternator by turning off non-essential electrical components like the radio, air conditioning, and heated seats.
  1. Charge the battery: If your car alternator isn’t working, you can manually charge the battery using a battery charger. This won’t fix the alternator, but it can give you enough battery power to drive a short distance. 
  1. Drive during daylight: If possible, drive during the day to avoid using headlights.
  1. Tap the alternator casing: Gently tap on the alternator casing with a hammer or wrench to jolt the internal parts back to life. Although it might temporarily revive a dying alternator in some cases, it could cause further damage and isn’t a reliable solution.  

Read on to find out if jumpstarting your car is a reliable solution.

Can You Jump-start a Car With a Bad Alternator?

While you can technically jump-start a car with alternator trouble, it won’t really help you drive for long. 

Why not?
Jumpstarting a car involves using another vehicle’s battery or jumper cables to supply power to the dead battery. This provides enough charge to start the engine and let the alternator take over. But, if you have a dead alternator, the vehicle’s battery won’t recharge. Eventually, your car may come to a halt as the battery’s reserve power gets depleted.  

So it’s always a good idea to fix your dying alternator permanently before you get stranded.

Wondering how much you’ll have to pay for a replacement?

How Much Does an Alternator Replacement Cost?

The car alternator replacement costs depend on the vehicle model, alternator quality, and labor charges in your region. Typically, you may have to pay around $600 to $1,000 to replace a failed alternator.

Note: With good driving practices and routine maintenance, alternators should be good for at least 7 to 10 years without any alternator repair.

Get Your Alternator Fixed at AutoNation Mobile Service

A faulty alternator can lead to various troubles, from discharged battery and headlight issues to complete vehicle breakdowns. 

That’s why you should avoid driving and seek alternator repair from experts like AutoNation Mobile Service.
We’re a mobile auto repair service available seven days a week. We offer upfront pricing, convenient online booking, and a 12-month, 12,000-mile repair warranty.

Contact us and we’ll fix your vehicle right in your driveway.