Can You Jumpstart a Car With a Bad Alternator?

Naomi O'Colman

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Can You Jumpstart a Car With a Bad Alternator?

Can You Jumpstart a Car With a Bad Alternator?

It goes without saying that a broken alternator should indeed be fixed as soon as possible, but what if you can’t, or can’t do so right away, and that it has led your battery to drain to the point where it requires a jumpstart? can you jumpstart a car with a bad alternator?

Can You Jumpstart a Car With a Bad Alternator?

The answer is YES. You can jumpstart a vehicle with a faulty alternator and keep it running for a while, regardless of how awful the alternator is.

This isn’t encouraged by any means, but it may be essential if you only need to drive a short distance. The purpose of jumpstarting is to get a dead battery to start, thus if you’re jumpstarting, your battery is probably dead.

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A jumpstarted battery will run flat faster than one that has been properly charged since it will not receive assistance from the alternator. Of course, if you have a large electrical load on, such as heating or phone charging, this can be hastened.

How to Jumpstart a Car With a Faulty Alternator Successfully

1. Obtain a jumpstart from a reliable battery

The first point should be self-evident. When you need a jumpstart because your alternator is broken, make sure the other vehicle’s battery is in good working order and fully charged.

The reason for this is that when you go to jumpstart your vehicle, your battery will be pulling a lot more power from the other battery than it would ordinarily.

2. Attach clamps

Please be careful and pay attention to the colors as below:

  • One RED clamp should be attached to the dead battery.
  • Connect the other RED clamp to the functioning battery.
  • Connect the BLACK clamp to the functional battery.
  • The other BLACK clamp was stripped down to the bare metal.

3. Allow the other vehicle to run for four minutes

Allow the driver of the donor car with a healthy battery to start their vehicle since the jumper wires are correctly linked. During this period, the vehicle with a flat battery should be shut off.

After roughly 3-4 minutes, try starting your vehicle, which has a dead battery and a damaged alternator. Wait 3 minutes and attempt again if the car spins a little but won’t start.

4. Make sure all of your accessories are turned off

Ensure that all electronic equipment in the vehicle is turned off. To draw power from the battery, turn off whatever you regularly use in your vehicle such as A/C, radio, or phone charger.

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5. Make way to the mechanic

If you were successful in jumpstarting your automobile using the other car’s good battery, head to the local technician right away. Before the vehicle’s electricity cuts off again, you may have another 5 minutes or so.

How Far Can a Bad Alternator Take You?

There is no clear answer to this question. There are too many elements that influence how long you can travel on a defective alternator, such as the alternator condition, the condition of the battery, or the car age.

A rough estimate would be 20 minutes or 13-15 miles, which can be increased if you go slowly and maintain your RPM low. If your battery is dead or you’ve just jumpstarted your car, don’t expect it to last more than 10 minutes or 10 miles.


When your alternator fails, there is no denying that you will have to replace it as quickly as possible. Meanwhile, a non-functioning alternator has most likely left you stranded because your automobile will no longer start. However, you may be able to jumpstart a vehicle with a faulty alternator in order to get the car back on the road and to a close auto repair shop.