Can You Jumpstart a Car with a Bad Alternator?

You can jumpstart a car with a bad alternator, but jumpstarting is only a temporary solution to get the car to a nearby repair shop before the car dies again.
Written by Katherine Duffy
Reviewed by Melanie Reiff
You can jumpstart a car with a bad alternator, but jumpstarting is only a temporary solution to get the car to a nearby
car repair
shop before the car dies again. 
We’ve all been there—you’ve gone grocery shopping in the middle of winter, only to return to a dead car after you’ve picked up dinner. You’ve just replaced your battery, so it seems ridiculous that you have to ask another customer to jumpstart your car…again. If it’s not your battery, why is your car dying? 
Chances are you’re dealing with a bad or faulty alternator. Your alternator is responsible for all the electrical components in your car, including charging your battery. So when your car has a bad alternator, the only permanent fix is to replace it. 
But what if your car dies while you’re out and you need to get it to a repair shop? Thankfully,
Jerry
, the
super app
for car insurance, has all the answers. We’ll go over whether you can jumpstart a car with a bad alternator, any dangers involved with driving a car with a bad alternator, as well as how far you can drive it. 
While we're at it, we'll even show you how to save on
car insurance
costs.
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Can you jumpstart a car with a bad alternator?

Thankfully, you can
jumpstart a car with a bad alternator
if your car is dead and you need to drive it to a mechanic. Here’s how to do it: Jumpstart your car from a car with a healthy battery.
This one should hopefully be obvious! To successfully jumpstart a vehicle with a faulty alternator, you’ll need to get a jump from a car with a good battery to get a decent charge. 
The bad alternator causes your vehicle’s battery to draw more power than usual, so it’s crucial that the other car has a healthy enough battery to handle this drain. 

Connect your jumper cables 

  • Attach one red clamp to the positive (+) terminal on the dead battery.
  • Attach the other red clamp to the positive (+) terminal on the good battery.
  • Attach one black clamp to the negative (-) terminal on the good battery.
  • Attach the other black clamp to an unpainted metal part (nut, stud, bolt head, or bracket) in the engine bay of the car with the dead battery. 

Turn the other car on for a few minutes 

While the car with the faulty alternator is turned off, run the car with the healthy battery for 3-4 minutes while the cables are attached. After a few minutes have passed, try to start the car with the bad alternator. If it doesn’t start, wait a few more minutes before trying again. 
Once your car starts, turn off all accessories that draw battery power, such as the radio, lights, climate control, USB ports, etc. to conserve battery power while you drive it to the nearest mechanic. 
You should only attempt to jumpstart a car with a bad alternator in clear weather conditions during daytime hours. 
You’ll need to turn off lights and
windshield wipers
to conserve battery power, so it’s crucial to stay safe and ensure you won’t need these accessories while bringing your car to the mechanic. 

What are the dangers of driving with a bad alternator? 

Your alternator is an important component of your car and delivers power to more than just your lights, radio, and other usual electrical suspects. Your alternator is also responsible for delivering power to key engine components, especially if you have a newer model. 
Here’s what may happen if you drive your car with a bad alternator: 
  • Electric
    water pump
    failure: Your water pump is often powered by your alternator and is responsible for pumping water from the radiator and moving it through the motor, keeping your engine cool. If it fails, your engine will overheat which can cause permanent damage.
  • Power steering
    failure: Some vehicles have electric power steering, which means that when your alternator is faulty, you risk experiencing steering difficulty. This will make it hard to turn quickly, putting you at serious risk on the roads. 
  • Fuel pump failure: Fuel pumps deliver fuel to your engine and are almost always electric, even in older cars. If you have a bad alternator, your fuel pump might fail, causing your engine to stop running. 
While any of these things are possible, it’s more likely that your car will stop running before any real damage can be done.
If your car shuts down again after jump-starting it, don’t test your luck. Call a tow truck to bring you to the nearest mechanic instead. 

How far can you drive with a bad alternator? 

The easy answer to this question is not far, because it’s tough to know precisely how far you can drive a car with a bad alternator without knowing exactly how faulty the alternator is. The distance you’ll be able to drive a car with a bad alternator depends on a few factors: 
  • State of the alternator
  • State of the battery
  • Electrical load 
  • Car age
  • Speed
In most cases, you’ll be able to drive your car for about 20 minutes, or around 15 miles, before your car shuts off. If you drive slowly and keep your RPM low, you may be able to extend this time period slightly. 
If you’ve jump-started your car, you have about 10 minutes, or 7 miles, to
get to a mechanic

How to save money on car insurance

If your car has a bad alternator, you have to replace it. Chances are, this replacement will be a surprise, and if you don’t have around$500stowed away to cover the costs, this surprise may totally throw off your monthly budget.
While it’s tough to save money on surprise repairs, you can recoup a large portion of these costs by saving your money on car insurance. That’s where
Jerry
, the car insurance
super app
, comes in handy. 
The Jerry app scans competitive quotes from top insurers in as little as 45 seconds to find you the best quotes for your car. They also re-shop your policy before each renewal; that way, you'll never miss out on a new deal. Jerry customers save on average $800+ per year on car insurance!
Jerry
had a super simple app that was easy to navigate. And their terrific customer service made everything even easier. Plus I saved $700 in a single year.” —Lucia M.
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FAQs

A new alternator can cost anywhere from $300 to $500 for parts and labor depending on your car’s make and model, the year it was manufactured, your location, and the mechanic you go to.
It’s not recommended to drive with a bad alternator because it can make driving risky. You should only drive a car with a bad alternator if you’re driving it to the mechanic.
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