Can You Jumpstart a Car With a Bad Alternator?

Is your car’s alternator faulty? You may have wondered – can you jumpstart a car with a bad alternator? Then, you need not worry anymore because you are in the right place; 

This article will answer some questions you might have if you have a bad alternator, such as, can you jumpstart a car with a bad alternator? How to jumpstart a car with a bad alternator, how far you can drive your vehicle with a bad alternator, and other related questions you might have. 

Let’s get started!

Jumpstarting a car with a bad alternator is not advised because your vehicle won’t go a long distance before the battery dies out because the alternator won’t be able to keep the battery recharged.

However, when you’re stuck on the roadside because of a dead battery caused by a bad alternator, knowing how to jumpstart a car with a bad alternator will be helpful.

The purpose of jumpstarting a car is to get your battery recharged, so if you have to jumpstart your car, your battery has died off because of the bad alternator.

Because the battery will not receive help from the alternator, an uncharged battery will be flat much faster than it would when it was correctly charged.

Naturally, this could be increased if you put a heavy electrical load on the car, like using the vehicle’s headlight, the heater,, or other similar electrical components.

Despite common misconception, the battery will not become completely drained even if the engine is started without first connecting the battery cables.

The car’s electrical systems will continue to function properly until the voltage level of the battery falls too low.

Also Read: Alternator Repair Options And Which You Should Choose

Functions of an Alternator in Starting a Car

Functions of an Alternator in Starting a Car

Your car battery provides power to your car air conditioner, stereo, headlight and other lights, heater, etc. Of course, this function of power production of a battery is essential, but have you ever wondered what keeps the battery alive and ensures the battery is charged? 

That’s where the alternator comes in. The primary function of an alternator is to make sure that the battery is working and the power from the battery is being transmitted at all times to the car’s electrical and electronic devices.

An alternator does the same thing as a phone charger: It charges the battery when the light comes on and while it is in use.

Therefore when the alternator is bad, the battery won’t be able to charge; instead, it will be drained out of energy, and the battery may die.

So what do you do in such a situation? Jump starting the car is your best bet.

What to Do Before You Jumpstart a Car With a Bad Alternator

Here are some safety measures to know before you jumpstart a car with a bad alternator

  1. Don’t allow touching of the cables.
  2. Ensure there is an adequate distance between the cars
  3. Don’t use the wrong wires, nor interchange them. 
  4. Keep off from touching the clamps
  5. Go through the steps listed below when jumpstarting your car. 
  6. Put on safety wears if handy.

How to Jumpstart a Vehicle With a Bad Alternator

How to Jumpstart a Vehicle With a Bad Alternator

To successfully jumpstart your car with a bad alternator, below are five steps to follow. 

1. Jumpstart From a Good Battery

Jumpstarting a car with a bad alternator will require the other car’s battery to be in good shape and well charged. This should be the first thing you look out for. If the vehicle is not fit enough or has a poor battery, please do not begin the jumpstart. 

This condition must be met because your car battery will draw lots of energy from the other battery, and if the other battery is not healthy enough, the jumpstart won’t work. 

2. Connect Jumper Cables

Here is how to connect the jumper cables:

  • On the dead battery, disconnect the one red clamp to the positive. 
  • One the good battery, do the same by disconnecting the red clamp to the positive. 
  • Same on the good battery; disconnect one black clamp on the negative terminal.
  • To provide adequate ground, disconnect the other black clamp, and place it on the painted metal part with the lifeless battery. 

3. Start the Other Car and Let It Run

After the adequate connection of the jumper cable, the donor car should be started and allowed to run for about four minutes. Again, remember not to turn on the dead car while doing this. 

After waiting for about 4 minutes, then start the car with the dead battery and bad alternator. It should start at this point, but try again after another three minutes if it doesn’t. 

4. Keep the Car Accessories Off

Turn off all electronic devices such as GPS, CD players, phone chargers, heaters, air conditioners, and other unnecessary devices that use your car battery power. 

This will help save up enough power to carry other necessary devices adequately.

Remember, this is best done during the daytime or when there’s an external light source because using the headlight could drain lots of power from the battery. 

5. Drive to a Repair Shop

As soon as you successfully jumpstart your car with a bad alternator, drive straight to a nearby mechanic because you don’t have much time on your side, and your vehicle can go off after 10 to 30 minutes.

Therefore don’t gamble on your opportunity; avoid highways or driving too fast. 

When you get to the mechanic workshop, get your car examined and run a complete diagnosis to verify and fix the alternator. 

Also Read: How To Charge A Car Battery Without A Charger (6 Best Ways)

How to Jumpstart a Car With a Bad Alternator Using Car Jump Starter?

How to Jumpstart a Car With a Bad Alternator Using Car Jump Starter?

A jump starter can be beneficial when you have a bad alternator or battery. Jumpstarters provide a huge amount of current; they are made of control electronics and lithium rechargeable batteries. Jumpstarters are not that expensive; they are relatively affordable. 

Jumpstarters are not so heavy, not too big, and can be carried around in suitable backpacks or compartments. However, don’t leave them in your car during the hot summer or winter. 

To use the jump starter, connect it to the positive and negative clamp of the battery, preferably start from the positive clamp, then put on the jump starter; it will analyze the battery, give you a signal, and then start your engine. 

Note: Don’t throw away the manual guide of a jump start after purchasing it; it would be helpful in some cases. For example, lithium jump starters are pretty different from most conventional jump starters. 

Is It Dangerous To Jumpstart A Car With A Bad Alternator?

There are no known dangers associated with jumpstarting a car with a bad alternator, especially if it is correctly done. It is a safe procedure; you don’t need to be worried about it. However, running a vehicle with a faulty alternator is very dangerous and catastrophic to your car. 

As you already know, alternators help charge your car battery, thereby powering car electronic and electronic components. Most modern alternators produce about 14.5 volts, while some Asian cars can get 15 volts. 

Since most new modern cars are designed to have high voltage, they equally dislike low voltage. Therefore, they can easily have components issues because of this; such problems include: 

Electric Water Pumps: The job of electric water pumps is to pump water from the radiator, transferring it to the motor for engine temperature regulations for the excellent running of the engine. Failure of the water pump will cause overheating and painful damage to the engine. 

Power Steering:  The power steering pump uses electricity for its operation. When your car’s power steering is bad, it will be challenging to steer quickly, which can cause an accident. 

Fuel Pump:  Fuel pumps are powered by electricity; even in old cars, when there is no electricity being transferred to the fuel pump, it won’t be able to supply fuel to the car engine for combustion. This can result in engine shut down and damage to engine components. 

There are factors surrounding the performance of a bad alternator and how long you can drive your car with it. Such factors include

  • The current condition of the alternator 
  • Battery current condition
  • Load level of all electrical and electronic components
  • The working age of the vehicle. 
  • Car model 

A rough estimation will suggest that you can drive a bad alternator for about 10-20 minutes. After that, you can be lucky to have more time to go at a lesser speed. 

Also Read: How Much Really Does An Alternator Cost?

What Are the Signs of a Bad Alternator?

What Are the Signs of a Bad Alternator

When the charging light remains on even after turning on the engine, or when the warning light flashes intermittently as the engine runs, that could be a sign of a bad alternator, and it will need to be serviced as soon as possible.

However, these signs are not always a result of a bad alternator; other factors could raise such problems. Therefore, the best thing to do is visit your mechanic for a proper check-up on your car to verify the actual problem. 

What Causes Alternator Failure?

The two primary causes of alternator failure are overcharging and heat. Your car voltage boosters or calibration regulators can cause overcharging when they get bad, while too much current drawn in the battery can generate overheating. 

Improper wiring can also cause overheating because there will be a poor connection and cause regulators to draw high currents. A poor connection can also cause the connecting component to warp or melt.

When your alternator gets too much heat, it reduces its functionality, which could make it get bad, causing damage to the bearing, windings, and internal diode. 

What Can Happen if My Alternator Malfunctions?

Malfunctioning of alternators comes with the poor performance of headlights, air-conditioning, heaters, and other electrical and electronic components.

Although in severe cases, such as the breaking or slipping of the belt that connects the engine and the alternator, there could be a total power outage in your car. 

You will also find driving challenging because enough power is not supplied to the car due to a fast battery drain. At a point, the belt will fail, and the engine won’t be able to run again. 

Regular inspection, examination, and maintenance of your car by a care professional will save you from the troubles and cost of alternator problems.

Frequently Asked Questions – Can You Jumpstart a Car With a Bad Alternator?

How Do You Know if Your Alternator Is Draining Your Battery?

When you remove the negative cable of your car battery while your car engine is still running, if your car dies out a few minutes or a second after removing the cable, it could mean your alternator is bad. Your car alternator lacks the power to produce electricity to keep the engine running. 

Why Won’t My Car Start Even With a Jump?

Corrosion of cable terminals is more often why your car is not starting even with a jump starter; therefore, brushing out and cleaning the corroded surface with a wire brush can help solve the problem and restore your car’s electrical power.

How Does a Car Act When the Alternator Is Going Out?

Your fuel injector will stop firing or face difficulty when firing when your faulty alternator stops working. A faulty or bad alternator can give room to broader problems; the earlier you resolve the issue, the better your car engine and your car’s general performance. 

How Do I Know if It’s the Battery or the Alternator?

Stalling a car engine after starting is most associated with an alternator problem. In contrast, if the engine starts and runs at the first start but refuses to start when you want to start again, it is probably a battery issue. 

Can a Car Be Started Without an Alternator? 

Yes, a car can be started without an alternator, however, it will only run till the car battery dies out.

Scott Greene is a seasoned automotive technician for over 5 years and has been deep into advanced automotive diagnostics for a couple of years. He Loves writing about Automotive Diagnostics and Repair, Trouble codes, Buyer guides for various car parts and accessories, and lots more. 

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