Car Won’t Start With New Battery – 13 Reasons (& What To Do)

You turn the key just to find out that your car won’t start. And since the battery is often the first thing to think about, you decide to replace the battery with a new one. It happens all the time, but sometimes simply replacing the battery won’t fix the problem. So what does it mean when a car won’t start with a new battery, and how do you fix it?

To answer these questions, we highlighted 13 different reasons a car won’t start with a new battery for you here, and we’ll even give you some troubleshooting tips to try and rule out each one.

So after reading this guide, you can figure out exactly what’s going on with your vehicle and get it running again in no time! Let’s start.

13 Reasons Why Car Won’t Start With New Battery

There are tons of reasons your car might not start even if you have a new battery. We’ve highlighted the 13 most common for you to consider here.

1. Car Isn’t In Park or Neutral

When you’re trying to start your car and can’t get it to turn over, your mind automatically jumps to the worst. And when you’re thinking through all those worst-case scenarios in your head, you’re not thinking clearly.

That’s why it’s always best to start with the simple stuff. Take a look at the gear selector and ensure it’s in either park or neutral before moving on to anything else. Your vehicle should only start when it’s one of these two gears, so if it’s not then it’s working just like it should!

2. Loose Battery Cables

You just put a new battery in your vehicle, and sometimes we forget the simple stuff. You need tight connections between the battery and the battery cables to start your vehicle, so if that’s not the case, you might run into a few problems.

Try gently pulling at the battery cables if they start to pull up, tighten them down and see if that fixes your problem. If it does, then there’s nothing else you need to do!

3. Faulty Alternator

If you replaced the battery and it worked for a few days before dying again, there’s a good chance the alternator is the real problem. Unfortunately, you won’t be able to take the battery back even if the old one is in good shape, but you’ll need to replace the alternator to keep your vehicle from constantly dying.

To test the alternator, use a multimeter or a voltmeter and put the black lead on a good ground. From there, put the positive lead on the back nut of the alternator with the charging cable attached to it.

With the engine running, the alternator should put out between 13.5 and 14.5 volts. If it’s pushing out less voltage, then you need to replace the alternator or the battery will keep dying.

But if you replaced the battery and you can’t get the vehicle to start even once, then the alternator likely isn’t the issue.

More: How Much Is an Alternator? (With Repair & Replacement Cost)

4. Defective Starter Motor

Your battery pushes voltage to the starter motor to start your vehicle. But if the starter motor isn’t working as it should then it really doesn’t matter how much voltage the battery pushes to it.

If the starter is the problem, you likely won’t even be able to get your vehicle to start once when you replace the battery. That’s because it doesn’t matter if the battery pushes 12.4, 12.6, or 13 volts to the starter if that’s the problem.

You can bench test a starter, but you’ll need a bench vise, jumper cables, and you’ll still need to remove the starter from the vehicle.

5. Faulty Ignition Switch

If you don’t hear anything when trying to start up your vehicle after replacing the battery, there’s a good chance the problem is the ignition switch. The ignition switch tells the ECM you’re trying to start the car, and then the ECM sends power from the battery to the starter.

But if the ignition switch isn’t working properly, then nothing is telling the ECM you’re even trying to start the vehicle. But if you hear a clicking sound from the engine or the engine tries to turn over at all, this clearly isn’t the problem.

6. Dead Key Fob Battery

If you have a newer vehicle with a push start system, you might not be able to get your vehicle to start simply because your key fob needs a new battery. Push start systems use a sensor in both the vehicle and the key fob to let the vehicle know when it should and shouldn’t start.

If the key fob’s battery is dead, then it won’t be able to push out the signal to start your vehicle. However, you can usually still start your car by using the key fob itself to press the push start button. This allows you to head out and get a new battery for the key fob to get it working correctly again.

7. No Fuel

Your vehicle’s engine needs fuel to run, and if it’s out of fuel then you’re not going to be able to start it up. The engine will still turn over and it will sound like it should start right up. But you’ll never get it started since there’s no fuel to take over after you stop cranking the engine.

You can check out the fuel gauge to see if there’s fuel in the tank, but keep in mind that sometimes the fuel gauge can give a faulty reading if something isn’t working properly.

8. Defective Fuel Pump

It doesn’t matter how much fuel is in the fuel tank if the fuel pump isn’t sending that fuel to the combustion chamber. The fuel pump picks up fuel from the engine and sends it through the fuel lines and through the injectors when the ECM opens them up.

The easiest way to tell if the fuel pump is working is to have someone else stand near the fuel pump when you’re trying to start up the vehicle. They should be able to hear the fuel pump kick on as it sends fuel to the combustion chamber.

If you hear the fuel pump turn on, that’s not the problem, but if it stays quiet, there’s a good chance that’s what is keeping your vehicle from starting.

9. Defective Fuel Injectors

The fuel pump picks up the fuel from the fuel tank, sends it through the fuel lines, and then it’s up to the injectors to send that fuel into the engine. But as the injectors age, they can get stuck closed or not open quickly enough.

When this happens, the vehicle will either start but have tons of misfires or not start at all. It’s not the easiest issue to troubleshoot. Typically, you’ll want to pull the injector out while trying to start the engine to see if it’s pushing out fuel when you crank the engine.

10. Damaged Timing Belt

While this isn’t the most likely reason your car won’t start even after you replace the battery, it is possible, and it’s likely the worst-case scenario. The timing belt connects the crankshaft and the camshaft and ensures they stay in the exact same cycle when the engine is running.

If the timing is off, the engine will run poorly, but if the timing belt or chain fails completely, you likely won’t be able to start your vehicle at all.

11. Locked Steering Wheel

If you can’t turn the key to start your vehicle, there’s a good chance the problem is a locked steering wheel. While a locked steering wheel can be an annoying problem, it’s actually an anti-theft device manufacturers install.

To unlock the steering wheel, gently turn the key to start your vehicle while gently turning the steering wheel in one direction. If it doesn’t work in the first direction you try, try unlocking the steering wheel by gently turning it the other way.

12. Wrong Battery

Your vehicle needs a battery with a certain number of cold-cranking amps to start your engine, even if it’s a brand-new battery. Check out the owner’s manual for your vehicle to see how many cold-cranking amps they recommend, then check out the battery.

If the battery isn’t meeting those minimum requirements, the problem could be you didn’t get a powerful enough new battery.

But while this is something you should consider, if you drive a typical car or truck, most automotive batteries can get the job done.

13. Faulty Starter Relay/Solenoid

In order to start your vehicle, electricity passes through either a relay or solenoid that clicks over to the correct position when the ECM tells it to. These parts rarely fail, but it is possible. If you don’t hear a clicking sound coming from the fuse box when you go to start the vehicle, this might be the problem.

The vehicle won’t try to start at all if this is the issue. To test it we recommend swapping the relay or solenoid with another one. They’re the exact same, so if the problem jumps to the one you swap it with, that’s the problem.

Final Thoughts

After reading this, you should have a good idea of what to check if your car won’t start after replacing the battery. These are the most common issues we see, but there are many other things that could keep your vehicle from starting too.

If your car still won’t start after going through this checklist, the best thing to do is take it to a qualified mechanic and have them diagnose the problem.

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Rickard Cefalk

Rickard is the owner of and a dedicated and avid do-it-yourselfer who has always enjoyed working on his own vehicles since childhood. He now devotes his time to sharing his expert knowledge of car maintenance and other car-related information through his website.

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