Can You Push Start a Car With a Bad Alternator?

A man pushing a broken down convertible car on the side of the road to push start it while the girl is behind the wheel

You turn your key, and your car doesn’t start — you might hear a clicking noise or no noise at all. This might mean that you have a bad alternator, but that doesn’t change the fact that you have somewhere that you need to go. In a last-ditch effort, can you push-start a car with a bad alternator?

Yes, you can push-start a car with a bad alternator and force the car to turn on. However, the alternator is responsible for recharging the battery. With a bad alternator, there’s nothing stopping your battery from draining and your car from dying. After a successful push-start, your time is limited before your car turns off due to a dead battery. The best option is to replace your alternator.

This is the question I’ll be answering in this article. I’ll start by explaining what a push-start is, how the alternator works, and I’ll let you know whether or not a push-start will work in your case.

Disclaimer: This Is Just for Manual Cars

Before getting too excited, I should mention that this technique only works for manual cars, not cars with automatic transmissions.

It also won’t work if you have an EV because electric cars don’t have a multi-geared transmission.

What Is “Push-Starting”?

Also called roll starting, this is a way of starting your car when you can’t start it the traditional ways. In other words, if you press the brake in while the vehicle is still in ‘Park’ mode and turn your key and nothing happens, you might be able to push-start your vehicle instead.

How does it work? Well, there’s a little engine called a starter motor. This piece requires a lot of electricity to get going, and it is responsible for starting your car’s engine. When your battery life is low, there might not be enough power to start the starter motor.

By pushing your car, you’re avoiding the use of this motor altogether. Instead, you’re starting with your car already in second gear and the vehicle moving.

Car gearstick manual shift knob with the 2nd gear highlighted in red

The reason why this technique won’t work with automatics is that you need to force your car into gear. That simply can’t be done with a car that automatically selects gears based on onboard computers.

There is an exception to this rule. Older automatics made in the 60s and 70s can sometimes be push-started since they didn’t include complicated programs to select gears.

Push-starting works when your battery has a little bit of life left and isn’t completely dead. For dead batteries, the only option is to jump-start or trickle charge your car. If you want the easiest method, you can get a portable car charger that will jump your car without the need for a donor vehicle.

The Role of the Alternator

The battery of your car is responsible for powering all the electronic parts of your vehicle. Most people understand that the battery powers your radio and lights, but it does more than that.

Your car can’t start without a healthy battery. If your car is struggling to start during a cold day, it is likely due to an unhealthy battery.

Essentially, your battery is always being used and drained whenever your car is running. That’s a big problem since you don’t plug your gas-powered car into the wall at the end of the day.

How does your battery recharge, then? This is where the alternator comes in.

How a car battery charges the engine starting system and alternator

The alternator serves a single purpose: to recharge your car’s battery. It’s a little motor with a belt connected to it. Whenever your car’s engine is running, the alternator is being energized. It will quickly spin around and deliver power back into your car’s battery.

A “bad alternator” can apply to a number of different defects, but the end result is the same. The alternator can’t recharge your battery quicker than your battery is being discharged. In other words, your battery will just slowly die with no means of recharging.

After enough time with a bad alternator, the battery’s life will dwindle and your car will stop running until you fix the alternator.

A Bad Alternator Is Different Than a Bad Battery

You should also know that a bad alternator and a bad battery are two different things. They will both present nearly identical symptoms in your car, but the troubleshooting and repair process is different.

With a bad battery, all you need to do is replace the battery. The process is pretty straightforward and doesn’t take anything special.

With a bad alternator, replacing your battery isn’t the right path forward. Since the alternator isn’t recharging the battery anymore, any battery you put in your car will slowly die. Instead, you’ll need to swap out your alternator with a functional one.

Quick Guide to Push-Starting

If you’re not sure how to push-start a car, I’ll give you a quick guide. Again, this only works for cars with manual transmissions and for batteries that have enough juice to power everything except the starter motor.

1. Start with a Clear Path

This is best to do if you’re on a slight downhill road, but it can be done on a flat one, too. Take some time to clear your path and make sure no debris will slow you down as you push your car.

You need about 400 or 500 feet in front of you to successfully push-start a car.

2. Turn the Key

Insert the key into the ignition and turn it to the “ON” section. Don’t keep the key turned as if you were trying to traditionally start it, just put it in this position and take your hand off the key.

Close up of a car ignition key hold where you insert the car key with ON highlighted

Doing this will also unlock your steering wheel. The power steering won’t be turned on yet, but you can finally move your steering wheel if you need to.

3. Put Your Car in Second Gear

Your best bet is to put your car in second gear. Technically, you can use first or third gear, but it will either require too much force to push the car or a speed that’s tougher to reach.

If your transmission has trouble in second gear, then I would suggest using 1st gear instead. Just expect a lot of hesitation and rumbling while attempting to successfully push-start the car.

4. Get Ready to Push

The final part before pushing is to make sure the driver is ready. They should disengage the parking brake and firmly press the clutch in completely, holding it there.

With the parking brake on, the pusher will have to push a lot harder to finally get the car moving. If the clutch isn’t pushed in, this process won’t work at all.

5. Push and Keep it Straight

Have the pusher start pushing. They should push against the trunk lid as opposed to a spoiler, tail light, or rear window. Another option is to open a door and push against the framework of the car. This requires a lot of empty space around you on the road and a quick reaction to close the door before the driver speeds away.

Man and woman pushing a car from the back that is broken down

The driver should focus on keeping the clutch fully depressed and the car straight. Again, you won’t have power steering, but you’ll still be able to navigate with a little elbow grease.

6. Pop the Clutch at Speed

Keep an eye on the speedometer. When you see it get above 5 mph (preferably above 10 mph), then you should quickly pop the clutch. This means that you take your foot off the clutch quickly, forcing your car into gear.

The faster you’re going, the better your chances are of a successful push-start. You can also give it a little gas when the engine kicks on to help your odds.

Your engine is going to sputter, and your car will probably buck as it turns on. If it was a success, then your engine will now be running, and your car will officially be turned on.

7. Quickly Get to Your Destination

Since your alternator isn’t good enough to keep charging your battery, you don’t have a lot of time to waste. In a traditional push-start, the driver would now take about 15 minutes to idle in place and let the battery slowly recharge. In this case, you won’t be doing that.

Instead, you should go to your destination before the battery officially dies.

Can You Push-Start a Car with a Bad Alternator?

In short, the answer is that you can push-start it, but your car will die once your battery runs out of juice.

Technically, there’s nothing stopping you from push-starting a car with a bad alternator, it’s very doable. However, the car will only run until your battery is completely dead.

A push-start works because the electricity needed to fire off your starter and turn your engine is higher than just idling your engine. By push-starting, you’re giving the battery some help to get things running.

New car generator alternator and belt installed on tensioned shaft

However, the alternator is bad. As I described earlier, your battery relies on your alternator to get recharged and keep you driving. Even though you can successfully push-start a car with a bad alternator, you won’t get very far.

If your battery is nearly dead, you might only have a few minutes. Short of driving yourself onto a towing trailer, there’s no real purpose to push-starting a car with a dead alternator.

Conclusion

Now you know that you can successfully push-start a car with a bad alternator. The only problem is that there’s nothing recharging your battery, so your car will eventually die again. If you want more car DIY tips, check out the rest of my site. I also have a list of products that can help you. If this article helped, drop a comment below and let me know.

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Ernest Martynyuk

An automotive enthusiast who's been tinkering with vehicles since I was 15-years old. Repairing automotive electronics has been my main job for over a decade now and have a passion for everything technical regarding cars.

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