Can You Jump a Car With a Bad Starter?

Dealing with starting issues can be frustrating. If you urgently need to get somewhere, jump-starting your car can sometimes do the trick. But what if your starter is faulty? Can you still jump-start your car?

Jump-Starting a Car With a Bad Starter

You can try to jump-start your car even when the starter is bad, and sometimes the extra current from an additional battery will spin a starter that is getting weak.

While there’s no guarantee it will work, it might be worth giving it a try, especially if you have to make that urgent trip. 

Most of the time, jump-starting will only work if you’re dealing with a weak or drained battery. The chances of it working are slim if you’re dealing with starter issues.

How to Start a Car With a Bad Starter

Here’s how to start your car if you suspect that your starter is bad:

Verify Whether Your Starter Is Bad

Before following the procedure below, make sure the battery is good and strong and the cable connections aren’t compromised. Next, depending on the vehicle, you may have a starter relay issue or a neutral safety switch. Try putting the gear selector in neutral to see if it starts that way. If it does, the neutral safety switch (transmission range sensor) may be faulty or misadjusted.

Make sure the battery is good and strong and the cable connections aren’t compromised. Next, depending on the vehicle, you may have a starter relay issue or a neutral safety switch. Try putting the gear selector in neutral to see if it starts that way. If it does, the neutral safety switch (transmission range sensor) may be faulty or misadjusted.

–Richard McCuistian, ASE Certified Master Automobile Technician

If the starter tries to engage but you hear a grinding or whirring noise when trying to crank your engine, the noise may indicate a faulty starter. But if the starter is simply loose and/or out of alignment, it can cause similar noises.

The best thing to do if your starter is bad is to replace it or have it replaced as soon as possible. But if you’re looking for a temporary fix, you can proceed with the steps below.

Check the Electrical Connections Going to Your Starter and Battery

Again, loose cable connections can cause starting issues, both at the battery or at the ground connection to the engine block. Turn off your engine, and visually inspect the cables and terminals. Tighten any loose connections. Make sure to observe safety measures while conducting inspections and repairs.

Check for Corrosion

Aside from fixing loose connections, it’s also recommended to check for corrosion. Corrosion can disrupt the flow of electric current, affecting the performance of your starter and battery.

Look for whitish, bluish, or greenish substances on your battery terminals, cables, and posts. You can use a commercial battery terminal brush and cleaner to clean your battery terminals.

To help prevent corrosion on your battery, consider using anti-corrosion battery washers and battery grease after cleaning it.

Gently Tap the Starter With a Hammer

A quick fix to get your starter to function temporarily is to tap it with a hammer or any metal you can find on your trunk that’s long and thin. Of course, if you don’t know where the starter is or can’t get to it, you won’t be able to do this.

If you’re traveling with a companion, you can ask the person to spin the engine while you tap the starter.

Why does this trick work? As stated earlier, the brushes wear out before anything else. When they are worn to the point that they aren’t making a good connection, tapping the starter can cause them to get a connection so that the starter spins.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: If the brushes are worn badly enough, no amount of hitting the starter will make it work. Hitting it harder isn’t the answer either.

You can try to start your car at this point. But if it doesn’t work, you can try to jump-start it. Make sure that you know the jump-starting basics before you do anything with your vehicle.

How to Determine Whether the Issue Is the Battery or the Starter

If you’re having a hard time starting your vehicle, you’re probably dealing with a battery or starter issue. But how would you know which one is causing the problem?

A mechanic can pinpoint the issue through different tests. However, if you want to at least have an idea, you can try the steps below:

Option # 1: Check Headlight Brightness

Watch the warning lights. if they come on bright and then go out or go dim and you hear a clicking noise under the hood, you might have a bad battery cable connection. If the starter is pulling too much current (and this is another way starters fail), the starter will pull the battery voltage down to the point that the lights dim. 

Turn the headlights on, then go to the front of your car to assess their brightness. After that, try to start the car again. If your headlights dim while you’re starting your car, you might be dealing with a weak battery or a starter that is pulling too much current.

Option # 2: Listen to the Ignition

When you try to turn on the ignition, determine if the starter starts producing a droning noise and slows down after a while. This sound could mean a problem with the car battery.

If the battery is almost strong enough to start the vehicle but the voltage goes below about 7 volts when you’re spinning the engine, some PCMs won’t even operate the injectors even though the engine is spinning and sounds normal.

Option # 3: Bench Test the Starter Motor

If you’re a seasoned automotive DIYer, you can also bench test the starter motor to find out if it’s functioning. The process usually involves removing the starter and then using a set of jumper cables to connect the starter to a battery while grounding the starter body.

The positive cable should be connected to the primary starter post and a jumper wire or screwdriver should be used to apply power to the solenoid S terminal. The solenoid should engage the starter and it should spin freely and smoothly if it works. If it just kicks in but doesn’t spin or spins slowly, the starter needs to be replaced. Make sure you’re using a good strong battery to test it.

Note that this process can be complicated. Don’t attempt to do anything with your starter or any component in your engine if you don’t have the necessary tools and know-how to do the test. When in doubt, you can always contact a trusted mechanic.

Is It Dangerous to Drive With a Bad Starter?

Yes. It’s not recommended to drive if your starter is malfunctioning. If it fails to start while you’re on the road, it can compromise your safety.

Also, a bad starter can put too much stress on components like the battery and alternator. You might end up damaging your engine more if you continue to drive.

Tapping your starter with a hammer is just a temporary fix. You’ll still have to replace your malfunctioning starter to keep your engine running at its best.

Where to Get High-Quality Starters for Your Vehicle

While jump-starting your car despite having a bad starter is possible, it’s best to replace the faulty part as soon as possible. Thankfully, CarParts.com has you covered!

Simply enter your vehicle’s year, make, and model into our vehicle selector to browse compatible starters for your ride. For a more personalized shopping experience, you can also use our search filters to find parts according to your preferred brand, price range, and more.

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Order now, and we’ll deliver your new starter straight to your doorstep in as fast as two business days.

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