5 Steps to Jumpstart a Car with a Bad Alternator

Last Updated on May 5, 2020

The alternator is what your car battery depends on to stay charged. With all the electrical components which exist in vehicles these days, you would never be able to supply energy to all of them with just the battery power alone. The alternator is what keeps the battery charged so that it can deliver the necessary energy to these components. So, what happens when you have a bad alternator? Can you still jumpstart your vehicle?

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When you have a bad alternator, there is no doubt that you will need to have it replaced as soon as possible. In the meantime, a bad alternator has probably left you stranded somewhere because your car no longer starts. Fortunately, it is possible to jumpstart your vehicle with a bad alternator so that you can get it back on the road and drive it to the nearest auto shop. The vehicle only needs enough electricity to power its onboard computer (engine control unit) and fuel injectors. If you can generate this much electricity, then it will be enough power to drive the vehicle to your local auto shop and get the alternator replaced.

The 5 Steps

Below are the 5 steps for jumpstarting your vehicle whenever you have a bad alternator. Just remember to be very conservative with your power as you attempt to drive your vehicle to the nearest auto shop.

1) Get a Jumpstart from a Good Battery – The first tip should be an obvious one. When you get a jumpstart with a bad alternator, you’ll want the other vehicle’s battery to be in good condition and have a full charge. The reason is that your battery is going to be drawing a lot more energy from this other battery than it normally would as you go to jumpstart your vehicle.

2) Let the Other Car Run for 4 Minutes – When you find someone to give you a jumpstart, their vehicle needs to be turned on and running for at least 3 or 4 minutes. Make sure the jumper cables are already connected as this is happening. Your car should be turned off during this time as well. After those minutes expire, attempt to start your vehicle which has the bad alternator in it.

3) Keep the Accessories Turned Off – Make sure all the car’s electronic accessories are turned off. This means turning off the heating, air conditioning, radio, CD player, GPS, phone charger, or whatever else you normally use in your vehicle to draw power from the battery. You’ll want to conserve as much battery power as you can so that it can successfully energize the computer and fuel injectors. Also, you’ll only want to attempt this during the day when it is sunny and there is no rainy weather. If you need to use your headlights or windshield wipers, then it will use up too much battery power.

4) Drive Straight to the Mechanic – If you were successful at jumpstarting your vehicle from the other car’s good battery, then drive straight to the nearest mechanic. You may have a good 5 minutes or so before the vehicle’s power shuts off again. Do not go on any major interstates or highways. Only drive on the slow-moving streets of your current location.

Read also: The Difference between 10w30 and 10w40 Car Engine Oil

5) (Optional) Jumper Pack – If you have a jumper pack handy, this could be another way to jumpstart your vehicle or at least give you a second jumpstart if you don’t make it the first time around. Some people keep these jumper packs in their trunk along with a spare tire. It might be a good idea for you to do that too in case you’re worried about breaking down as well.



  1. My car will not start. I got jumping cables and another car to recharge battery. When connected 3 cables and tried to finish with the last one ( either one, + or -) ., I checked all possibilities My car starts like an alarm signal. I could not charge battery. What ‘s wrong?

  2. I have a 2008 Dodge Nitro, my husband left the key in the on position. Now Nitro won’t start at all. So I went through 3 alternators. Still will not start. PLEASE HELP CAUSE WE ARE GOING THROUGH A DIVORCE AND I KEEP THE KIDS I NEED MY VEHICLE. PLEASE ANYONE IM BEGGING !!!!!!!

    • If the key was in the ON position, the battery is probably dead. You could charge the battery or jump it, then attempt to start the car again.

  3. Yesterday my car didnt want to start. Has a month old battery and dash lights/headlights/radio all turned on. Once i tried to crank the engine, nothing happened, not even a click. I was told its the starter so I immediately went to buy one, got a mechanic to come out today, and when i tried to use the key fob to unlock the car it didnt work. My brand new battery has drained over night. Is it possible that my starter and alternator failed at the exact same time? Or is there somehow a connection between the starter and the battery failing

    • Are you sure the battery in the key is good? Check that, and make sure the battery terminals are clean and tight. Corrosion at the battery terminals may cause a good battery to fail to even crank the vehicle.


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