The ground strap is not something you commonly hear. But you probably know that your car has a negative battery cable, the black wire that connects to your car’s battery. And yes, the ground strap is another name for the battery’s negative cable. It’s often overlooked, but it can be the cause of the electrical problems in your car. We’ll be looking at bad ground strap symptoms in this post.
We’ll also explain why it’s important, how it affects your car, and of course, the cost estimate for replacing a bad ground strap.
How Does Ground Strap Work?
This may be a bit difficult to follow but bear with us. First, you need to know that the electrical system in your car is a closed-loop system. Now, a closed-loop circuit typically requires a grounding device. Grounding provides a safe path for stray voltage to follow, and in your car, the electrical circuit uses the car’s engine and chassis as ground.
Here’s how it works: electricity flows out of the battery’s positive terminal through the positive cable. Engineers often refer to this as the “hot wire“, as an active voltage is flowing through this cable. The electricity then travels to the electrical accessories in your car that need it, such as the radio, the headlights, and the starter motor. These accessories also have a grounding wire that connects to the car’s chassis.
This provides a safe path for the stray voltage to discharge. Meanwhile, the black negative battery cable, which is the ground strap, also connects to your car’s chassis. If you take a look in your car, you’ll notice it has two connections: one to the engine block which serves as a ground for the ignition system. And you’ll notice it also connects to the chassis.
As mentioned, the stray voltage coming from your car’s electrical accessories will travel through the chassis. And then into the connector that connects to the battery’s terminal. This completes the loop of electricity from the positive terminal, back into the negative terminal. Hence why it’s called a closed-loop, as electricity discharges back into the battery.
Why Is Grounding Necessary?
Confused? Don’t worry, no need to think too much about it. Unless you have a degree in electrical engineering, this sort of thing is going to be hard to understand. All you need to know is that grounding provides a safe path for stray voltage to discharge. Without it, things can get quite dangerous.
The stray voltage will cause power surges, which can damage your car’s electrical accessories. It can also shock people nearby, as the stray voltage has nowhere to go. And it can even lead to a fire. None of these things is something you want to happen in your car.
If you want to learn more, we recommend reading more about electrical circuits here. The video above also provides a great explanation of how your car’s battery and its electrical system work. But to summarize, the ground strap is there to connect your car’s chassis and engine to the negative battery terminal. This provides a safe path for any stray voltage to travel back into the battery, avoiding damage to the electrical accessories in your car.
Bad Ground Strap Symptoms: What To Lookout For
Now that you know how the electrical system in your car works, we can discuss the bad ground strap symptoms. Here are the signs that you have a bad ground strap:
1. Flickering Headlights
The first bad ground strap symptoms you will see are with your headlights. If you have an older car with halogen headlights, you’re going to experience flickering headlights when you have a bad ground strap. This is because when the ground strap is damaged, there will be resistance in the electrical circuit.
As a result, this interrupts the electric current and results in a flickering headlight as it’s not getting a constant voltage. If you have LED headlights instead, it may refuse to turn on entirely.
The headlights may also dim, but dim headlights usually happen because of a bad alternator. This is because an alternator powers your car’s accessories and the battery when the engine is running. If the alternator isn’t putting out enough power, it can result in dim the headlights.
Anyway, this can happen as well if the ground strap is loose. Check if it’s loose, and tighten them as necessary. If that doesn’t fix the problem, you likely have a bad ground strap.
2. Dead Battery
The battery in your car is consumable, just like the battery in your iPhone. Meaning they become less effective over time, and will eventually be unable to hold a charge and die out entirely. Of course, most car batteries will last at least a year, sometimes up to two or even three years depending on the quality and the electrical demand from your car.
If your battery is still relatively new but it’s already dead, there are two possible culprits: a bad ground strap, or a faulty alternator. The ground strap helps to charge your car’s battery. If the ground strap is bad or loose, then the battery won’t be able to charge properly.
Meanwhile, as mentioned, the alternator is also in charge of charging your battery while the engine is running. A faulty alternator won’t put out enough current to charge the battery, leading the battery to die much quicker than it should.
3. Problems Starting Your Car
The car is a very complex piece of machinery, so there’s a myriad of possible causes on why your car won’t start. If it’s because of a bad ground strap, you will likely hear tapping sounds when you turn the key to start the car.
This tapping sound comes from the starter motor’s solenoid. When the ground strap is bad, the starter motor won’t get enough voltage which leads to the solenoid opening and closing rapidly. If it doesn’t get enough voltage, then the starter motor won’t be able to crank the engine, which is necessary to start the engine.
4. Warning Lights On The Dashboard
Your car has a bunch of warning lights on the dashboard to warn you when there’s a fault. There’s the check engine light, the oil warning light, the ABS warning light, and of course, there’s a battery warning light as well. When the battery warning light is on, this typically indicates that the battery has a low charge and isn’t being charged properly.
Of course, there could be several reasons for this. A faulty alternator, damaged wiring, and yes, bad ground strap as well. If you’re driving and you see the battery warning light, we recommend switching off the electrical accessories. Switching off the air-conditioning, seat warmers, and the radio will help to preserve charge in the battery. This can let the car run longer, helping you to get where you’re going.
Because a bad ground strap can cause electrical surges, this can trigger a check engine light and other warning lights as well. But these may be a “false” warning light due to the electrical surge. However, if you’ve replaced the bad ground strap or you’re sure it’s in good condition, there’s another problem with your car that’s triggering these warning lights.
Use an OBD scanner to help identify the problem, and then fix them before it gets more serious.
5. Weird Electrical Problems
If you switch on the air-conditioning but then the windows roll down on their own, don’t worry, your car isn’t haunted. Chances are you have a bad ground strap, not a haunted car. A damaged ground strap ruins the closed-loop nature of the system, leading to electrical surges.
These surges can send voltage to the wrong electrical accessories in your car. As a result, they will turn on and activate on their own. So, don’t worry, your car isn’t haunted. But to be honest, a bad ground strap sounds scarier to us than a haunted car.
Anyway, these are just the symptoms and there are several possible culprits. So, you’ll need to diagnose whether it’s the ground strap or something else that is causing the problem. Here’s how you diagnose it:
Bad Ground Strap Symptoms: Diagnosing The Ground Strap
The first thing you should do is a visual inspection of the ground strap itself. The ground strap can either be a braided metal wire, or a black cable. Either way, they connect to the battery’s negative terminal, and then onto the car’s chassis. See if there is any damage to it. The slightest sign of damage such as an opening (if it’s a cable) can cause it to go bad.
If you see the damage, then this is confirmation that the ground strap is bad and you will need to replace it. Keep in mind there are several ground connections in your car, such as the negative cable that connects to the engine block. You’ll have to locate them and check them one by one and see if they are okay.
If you don’t see any physical damage, then you can test its condition by using a multimeter. Here’s how:
Testing With A Multimeter
- Park your car in a dry area, and get a hold of a multimeter.
- You’ll be working with electricity, make sure to remove any jewelry and that the engine bay is dry, just to be safe.
- Set the multimeter to the 20volts Direct Current (DC) setting.
- Connect the red probe to the positive battery terminal, and the black probe to the negative terminal. It should read around 12.06 volts.
- Afterward, connect the black probe to the ground connection (the ground strap that connects to the chassis). It should also read around 12.06 volts. If it reads below that, this means that a particular ground strap is bad.
- Next, connect the black probe to a metal surface on the engine block. This tests the ground connection to the engine, and it should also read around 12.06 volts. An abnormal reading means you have a bad ground strap to the engine.
If you need a visual guide, watch this video below:
As a reminder, there are multiple ground cables in your car. So, you’ll have to check them one by one and see which ground strap has gone bad. If they all seem fine, then you have another problem with your car. Flickering headlights and a dead battery usually mean you have a bad alternator.
Meanwhile, a blown fuse can cause weird behaviors with electrical accessories in your car. If your car is refusing to start, we recommend reading our guide on how to troubleshoot a car that won’t start here.
Bad Ground Strap Symptoms: Replacement Cost
Once you find the bad ground strap, the next course of action is of course to replace it. The cost will vary depending on your car’s make and model but expect the cost to be somewhere around $20 – $80. Around $10 – $50 will go to the ground strap itself, and $10 – $30 will go into labor.
Replacing Bad Ground Strap: DIY
The replacement cost for a bad ground strap is cheap, but if you want to do it yourself, you can as well. You won’t save a lot of money, but hey, nothing wrong with being thrifty, right? The difficulty will depend on where the ground strap attaches to, some may be more difficult to replace than others.
In any case, you’ll be working with battery and electricity. Follow these safety precautions to avoid painful injuries:
- Park your car in a dry area, ideally indoors but with good ventilation. A bad battery can emit toxic gases. If you smell rotten eggs coming from your battery, it’s a good idea to replace the battery while you’re at it. Ideally, you should call a professional technician to help you replace and dispose of the bad battery.
- Turn off your car.
- Make sure the engine bay is dry and free from moisture.
- Remove any jewelry on you, including rings, watches, etc.
After you follow the safety precautions above, here’s how you replace the bad ground strap:
How To Replace Bad Ground Strap
- Disconnect the negative battery cable (ground strap) from the terminal. Most commonly you’ll need an 8mm wrench to loosen the bolt, and then you can remove the cable from the terminal.
- The other end of the negative battery cable may be difficult to access, so remove the positive battery cable if necessary to gain access.
- Untighten the bolt that holds the other end of the negative battery cable, and then remove the cable.
- Install the new negative battery cable in place and tighten the bolts on both ends.
- Once everything is connected, start your car and see if everything’s working properly. You can also test the battery with a multimeter to see if everything is working well.
The process may vary a bit depending on your car. But that’s the general guide on how to replace the ground strap or the negative battery cable, and the video above is a great visual guide.
Keep in mind, when we say “ground strap”, there are several ground straps in your car. And any of them can go bad, in which case you’ll have to replace them. But the method is largely the same: disconnect at both ends, and then install a new one. The difficulty is going to vary depending on where the ground strap is located.
Bad Ground Strap Symptoms: Questions & Answers
Those are the bad ground strap symptoms, replacement costs, and how to replace it. Got any more questions about your car’s electrical system? We’ll answer as many as possible below:
Can I Drive With A Bad Ground Strap?
No. First of all, a bad ground strap may cause your car not to start at all. Either because your starter motor isn’t getting enough voltage, or your battery will die due to insufficient charging. So, a bad ground strap may prevent you from driving your car in the first place.
Secondly, even if your car can start, this is a bad idea. Partly because many electrical components won’t be working properly. For example, your headlights may flicker or even shut off completely. At best this will earn you a ticket, but it can also lead to accidents when you drive at night as visibility could be poor.
It’s a bad idea mostly because a bad ground strap has the potential to be a fire hazard. As mentioned, the ground strap is there to discharge stray voltages safely. It ensures a safe path for any stray voltages back into the battery, so they won’t escape. If they escape, it can start a fire, or shock people when they happen to touch something that’s receiving this stray voltage.
So, no. Don’t drive a car with a bad ground strap.
How Long Do Ground Straps Last?
There isn’t an estimate on how long a ground strap can last. Speaking from experience, I’ve had plenty of cars that are over 10 years old and none of them have had any ground strap problems. They may wear out quickly when there’s excess heat in the engine (because of an overheating engine, for example) as thermal stress can wear these cables down.
Physical damage can also occur if the car has been in an accident that happens to affect the cables. Or improper installation where the cable bends excessively can also damage the wiring inside the cable. But most of the time, you needn’t worry about replacing the ground strap frequently. They don’t require any maintenance either.
My Battery Is New But It Died, Can I Revive It?
As mentioned, a bad ground strap can affect the battery’s recharge process. If the battery isn’t getting enough current, then it can die quickly. So, the question is, if your battery is still new but it died, can you revive it? Can you recharge it fully? Yes, you can, as long as your alternator is in a good condition.
What you need to do in this situation is jumpstart your car’s battery. And then make sure the ground strap is good, and you have a good alternator. You can test your alternator by using the multimeter: connect the probes to the battery, and if it reads somewhere between 13.5 – 14.5 volts, then you have a healthy alternator. If not, you’ll need to replace the alternator.
If you have a good alternator, then drive around in your car for about 15 minutes with the electrical accessories off. This includes the headlights (if you’re doing this in daylight), the radio, and the air-conditioning system. This will recharge your car’s battery, bringing it back to a charged state and ready to use the next time you start the car.
Keep in mind that once a battery dies, its lifespan may be shorter than what it’s rated for. So your battery might still not live as long as it should, but you can keep using it for now.
Are Ground Straps and Ground Cables The Same?
The term “ground strap” and “ground cables” are often used interchangeably. But ground strap usually refers to the braided metal cables, while ground cable refers to the black cable you often see on the battery. However, both serve the same purpose of grounding your car’s electrical system.
As for which one you should use, we recommend using whichever was present in your car. If your car was using a ground strap, then replace it with a ground strap. The same goes if your car was using a ground cable.
Bad Ground Strap Symptoms: In Conclusion
Now you know the five common bad ground strap symptoms. You’ll notice erratic behaviors from electrical accessories, warning lights, and your battery will possibly die as well.
Electrical problems in your car will mostly stem from either a bad battery, a faulty alternator that isn’t charging properly, a blown fuse, or a bad ground strap. Having a multimeter will be very handy, and can help you identify electrical problems in your car.
If you have a bad ground strap, we recommend replacing it immediately. Not only this will allow the electrical accessories in your car to operate smoothly, but it will also be much safer for you to drive. They’re mostly around $80 to replace including labor and is a pretty easy job to do yourself if you want to. Good luck!
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