car ground strap

Ground Strap Symptoms: Information & How to Fix It

In Electric by Magnus Sellén3 Comments

If you are having electrical problems with your car, the problem could be a bad ground strap.

The ground strap is connected to the car battery’s negative terminal.

It is also called the negative battery cable. Almost all of the car’s electrical components are connected to this cable.

When you start having problems with the ground strap, it will lead to other car problems.

Signs of a Bad Ground Strap

ground strap

A bad ground wire can cause a lot of strange symptoms with your car’s electrical system. Here is a list of the most common signs to check for.

1. Flickering lights

The ground strap will with time become loose and cause some resistance to the headlights. In this case, you will experience flickering lights. If this is not rectified, it can damage your headlights. The flickering lights could be an indication that the ground cable is loose.

The cable is not usually properly insulated and with time it can become loose. You can tighten it if it’s loose or simply replace the whole unit if it does not change even after tightening.

2. Battery not charging properly

If your battery is not getting charged fully but the alternator is functioning well, the problem could be with the ground strap. A battery that is not charging properly can be caused by many factors such as defective terminals or an aging battery.

You will need to rule out all these factors before concluding that it is the ground strap that is the problem.

3. Low voltage

Another sign of a faulty ground strap is that you have low voltage circulating in your car. A simple voltage test will reveal whether you are receiving full power. A well-functioning battery should give you a reading of around 12.6 volts. Anything less than this is an indication of the battery not being completely charged.

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4. Problems starting your car

If low power is flowing to the ignition system and stator, then your car will not start. The car may also not start due to engine problems or lack of fuel. However, if the problems with starting are accompanied with any of the above symptoms then the problem can be a bad ground strap.

Problems with the stator solenoid will often be accompanied by tapping sounds. This means there is power but it is not enough to start the stator.

5. Visible damage of the ground strap

You can confirm that you need a new ground strap by performing a physical examination of the ground strap. If it seems to be loose, then you can tighten it but if the wires are worn out it is prudent that you have your mechanic replace the entire unit.

Causes of a Bad Ground Strap

car electronics

The ground strap will wear due to age and vibrations and it’s a good thing to replace it and clean the surfaces if it looks bad.

You know you have electrical ground strap problems when the audio system starts becoming noisy or the fuel pumps are always on low pressure.

For many people, the assumption is that whenever the ground wire is connected to some part of the car then it is properly grounded. However, for the ground wire to be effective, it has to be placed on a part that is free from paint or rust. This is because paint and rust act as insulation in the car and offer a bad ground strap.

When you are grounding the strap, it is good practice that the wire runs through the alternator case while ensuring that it is not coming into contact with the paint.

Functions of the Ground Strap

The ground strap is a wire that runs from the engine chassis to the block. In some instances, it is connected to the negative terminal. The circuit is complete for all electrical components in the car. Some of these components include the alternator and ignition system.

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The problem with bad ground straps is that they are often steel wires interwoven together. This means they lack any form of insulation. As you continue driving your car, the steel wires will snap; hence, affecting your ignition and alternator. The ripple effect is that you will constantly have a dead battery, experience loss of car power or have cylinder misfires.

Fixing the Bad Ground Strap

Firstly, you need to identify the negative cable. In most instances, this is often the black cable. When it is black, then the positive terminal is the red one. Some batteries have identified the terminals as +ve and –ve.

You can use a wrench to loosen the connection of the negative terminal from the battery. In some instances, you may need to pour some soda so as to clearly view the terminal. It is optional to remove the positive terminal as no current will be flowing to the car. You should now carefully follow the ground cable from the battery to where it is attached to the car.

If the cable is damaged, use a wrench to remove it. Search for a suitable replacement ground cable and reattach it back to the battery terminal. Ensure you have tightened all the bolts. Replace the positive terminal and your electrical components should start working well again.


The ground cable is an important component of the car’s electrical system. In some cases, it is referred to as the negative battery cable. The wire comes all the way from the negative battery terminal and is connected to the chassis. When the cable becomes loose, you will start experiencing all types of electrical problems.

Firstly, the headlights will start flickering anytime you turn them on. A closer inspection of the car’s voltage will reveal that your car is running on low voltage. The car’s battery may also fail to charge as usual. A good battery should have a voltage reading of 12.6 volts.

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If the ground wire strap is faulty then your battery will not charge completely. This will lead to further problems like starting the car in the morning. Once you realize that your ground cable is worn out, remove the cable from the negative terminal and replace it with a new one. This often works. You can do yourself but you can contact your mechanic if you have problems locating it.

3 thoughts on “ Ground Strap Symptoms: Information & How to Fix It ”

  1. I honestly did not know a faulty earth strap could cause me so much grief and an always out of pocket expenses. But to be exact of my question, how many earth straps in particular is needed for a 304 5litre engine in a vr vs commodore and what components should they run from to the chassis…

    Many Thanks

  2. I have a 1990 yamaha fzr 600. Sport bike its been mostly custom built can someone please help i think i have a bad earth ground because the motor was working fint telii i took it of the bike ti split case for new trans gears i put it all bake togethe its on the bike loom seams to be hooked up rite but i have no spark at all everything else seems ro be fine and working any idea’s

  3. Okay, Purchased used, a 2010 Jeep Patriot 2.4L, 4WD, with a CVT Transmission. The amount of small features that either need or are just connected to one of the electronic monitoring systems. It’s because of all the electronic monitoring systems that are installed, the vehicle is irritating and in my opinion, nothing short of plain overkill. When the ”Check Engine” light comes on, some of the options will not work and some only work part of the time. With that said, here’s two of the issues that the Patriot’s have issues with but there is hope & light at the end of the tunnel. The ”Airbag” Light. That was 1 of 2 warning lights that were staying on all the time. Although I was able to get that one to stay off, other than ”Startup System Monitor. Last is the ”4WD!” Light. Whenever that light comes on, it will not allow you to access the 4WD at all. I was able to get it to stay off for about 1 – 1 1/2 weeks but now it comes on whenever I travel to 1 mile. I use the ”Trip Meter” #2 as a way to keep tabs on it. Since it always comes on right at 1 mile, leads me to believe that one of the monitors takes that long to complete it’s test cycle. I just happen to look at the ”Ground Strap” which comes from the cabin side of the engine, over to the firewall. Apart from being completely green, it’s very brittle, and so full of corrosion that it’s dried out and starts to slightly fall apart whenever I wiggle it. Plus it has a cut that is about 50% of the way through the cable. I plan on replacing it today or tomorrow and if that 4WD! Light does go off after I install the cable, I will either edit this comment, or type in another question below mine, unless someone else adds to the comment. I believe that it is the problem.

  4. Due to very high demand and a high amount of comments, you might have trouble getting your comment answered by me. If you want to get fast answers from a certified automotive technician you should ask your questions here: Ask A Mechanic

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