Ground Straps: Why are They Essential for Automotive Applications?

FACTS CHECKED BY  Jose George​

How do airplanes fly through the clouds in bad weather? Clouds are electrically charged and decimate voltage of more than 100,000 V, and they hit airplanes. Even if there are no terrible clouds, the air at a higher altitude can statically charge the aircraft. Static electricity has the potential to harm the system or the people involved. The answer is limited to two words: ground straps.

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Similarly, cars use ground straps to avoid electrical damage. How do they work? Let’s find out the answer.

Why do Cars have a Ground Strap?

Ground straps, or earthing straps, provide a safe path to electricity to minimize damage. It has a braid of metallic wire having one terminal at both ends. Also, manufacturers use copper because of its excellent conducting ability and cover it with tin to protect the strap from corrosion.

Tin is an essential element that protects the electric control unit and other components of the car. Also, Tin Plated Copper can ground the static electric charges due to air and tire friction. In that case, you will hang the ground strap from the undercarriage. 

How Does a car’s Ground Strap Function?

The ground strap is a bridge between power and safety for automobiles and aircraft. It functions between the car engine, battery, alternator, and chassis. It provides a safe path for the return of the electricity and closes the circuit, thus providing safety measures to the electrical components of the vehicle.

Once the car starts, the positive charges traverse from the positive terminal to other components of the vehicle and return to the negative terminal. The ground strap provides this return path to the battery’s negative post. This return path closes the circuit, and as a result, the current does not flow. 

Where Can We Find the Ground Strap in the Vehicle?

Automobile manufacturers use ground straps to make vehicles safe. Since different electrical components have their grounding wires under the engine hood, people confuse ground straps with grounding wires.

Ground straps link to the inner chassis or engine block to create a return path for the current. Also, you will connect one end with the battery’s negative post and the other with the chassis or engine block.  

Caption: Orange Strap wire

Why Prefer a Ground Strap Over a Ground Wire?

Vehicle manufacturers used to attach thin cables or wires to ground the current or charges. However, a ground strap is a better fit for this purpose. A ground strap is a collection of thin wires that offer a wide length, creating low resistance, and higher conductivity, enabling a more reliable current flow.

Another advantage of using ground straps is their flexibility and durability. Given these facts, it would be wise to opt for ground straps compared to the thin insulated wire.

Why is Ground Straps Important at all?

Since ground straps are used to close the circuit, you must use them to protect your vehicle from damage. They provide a path for the electric current to flow within the vehicle. Without the strap, there is a high chance that your vehicle may break down or suffers from a short circuit. 

Additionally, the ground strap ensures that the battery operates at a consistent voltage. When you do not use ground straps, the chances for a short circuit go high. Because the current begins to travel on the wires that are not meant to carry it.

You have to make sure to install high-quality and good-condition ground straps. Failing to do so may leave you with a broken ground strap that would cause a system malfunction. Repairing and troubleshooting ground strap-related problems may take a long time; therefore, always installing high-quality equipment is good.

How do Bonding and Ground straps differ?

Bonding and ground straps may give off a similar vibe but differ significantly in functionality. They serve as a bridge between the two components to retain a similar electrical potential. They protect the vehicle owners or drivers from the shock.

The bonding strap stabilizes the electric current between the two components, whereas the Ground strap provides a safe passage for the current to flow in case of a voltage surge. Both straps work together to maintain the current flow in the vehicle.

The choice for ground straps

A wide range of ground straps is available per the requirements.

Choices for strap type

  • Braided: Braided ground straps consist of several wires interlaced together.
  • Grid: They are commonly available.
  • Sheet: These are rectangular grounding straps. 
  • Solid wire: These straps are confined to one single solid wire

Choices for strap materials

Best ground straps have excellent conducting properties, which are essential for a good current flow.  Following are some of the materials that are used in present-day ground straps:

  • Aluminum
  • Copper
  • Tinned copper
  • Stainless steel
  • Nickel-plated materials
  • Silver plated materials

From the given list, opt for copper due to its reliable conducting properties and low price compared to other materials. We recommend a stainless steel ground strap for corrosion as it is more reliable in withstanding moisture, chemicals, and saltwater. 

Choices for strap shapes

Ground straps are either tubular or flat but can be custom-built using specialized conductors from different suppliers.

Choices for strap American Wire Gauge (AWG) sizes 

  • 4/0
  • 3/0
  • 2/0
  • 1/0
  • 1
  • 2
  • 3
  • 4
  • 6
  • 7
  • 9
  • 10
  • 12
  • 14

Choices for terminal types

You must choose the right terminal connectors to ensure good compatibility with the strap. 

  • Ring Terminal
  • Square Lug Terminal 
  • Fork Terminal
  • Alligator Clamps 
  • High-temperature Terminals
  • Solder Dipped and Punched
  • Crimped Ring
  • Ground Strap Types and Variants

Choices for additional ground strap design

  • Flexible Braided Grounded Straps: These straps have several wires interwoven together to provide low resistance and greater heat escape enabling higher amperage current flow. 
  • Insulated Ground Straps: These ground straps have a rubber film to contain current and heat. Insulated Ground straps use color coding to highlight grounding. 
  • Automotive Ground Straps: These ground straps are essential to close the circuit and connect the engine block with the battery’s negative post.
Strap in circuit breaker

Caption: Strap in circuit breaker

Symptoms of a Bad Ground Strap

Bad ground strap? 

Flickering Headlights

If your headlights are flickering, know that you have a bad ground strap. Headlights flicker when there is resistance to electric current. Higher resistance means lower conductivity of the ground strap. When the resistance is higher, the ground strap is not working properly.

Warning Lights

When the battery warning light appears on the dashboard, there may be a reason that you may have a bad ground strap. It is necessary to check all the relevant warning lights before you embark on a long journey.

The battery is not charging correctly.

Car batteries are similar to Walkman cells. It means they become less effective over some time. However, if your battery is relatively new and does not respond as it should have, then it means that you have a bad ground strap. Since it is responsible for charging the car battery, a bad ground strap may not charge it effectively.

Problems starting your car

 Whenever you hear a sound while starting your car, it will be most likely because of a bad ground strap when you hear a sound while creating your car. Since the ground strap is responsible for generating the voltage flow, a bad ground strap fails to do so, due to which the solenoid rapidly opens and closes. This action results in the voice whenever you try to start your car, but it doesn’t.

Strange Electric Problems

Ever wondered when you turn your stereo on, your windows automatically start to roll down. This symptom in itself highlights that you have a bad ground strap. Since a good ground strap avoids voltage surges, a bad ground strap causes the opposite and does not provide a closed loop for the electrical current to flow.

Diagnosing the Ground Strap

You should visually examine the ground strap itself as your initial step. Check to see whether it has any damage. If it’s a cable, even a small opening could indicate damage, which would make it faulty.

If you see the damage, this proves the ground strap is defective and needs to be replaced. Remember that your car has several ground connections. So, you’ll need to find them and examine each one separately.

Replacement Cost of the Ground Strap

The next step is to repair the damaged ground strap once you’ve located it. Expect the price to range between $20 and $80, depending on the make and model of your car. $10 to $50 will be spent on the actual ground strap, and another $10 to $30 will be used for labor.

How to Replace a Negative battery ground cable

To replace a negative battery cable, you will

  • Identify the ground strap or the negative battery terminal of the car
  • Now, disconnect the negative and the positive (optional) cable from the car battery
  • Remove the battery from the chassis
  • Next, remove the bad ground strap and install the new one. Once complete, fix the elements back to their places.

Conclusion

Ground straps play a critical role and provide a closed loop for the current to flow. If the loop is not closed in case of a short circuit or voltage surge, the current may seek to use the human body to reach the ground. It would be deadly for the driver or other electrical components of the car. Here at Cloom, we offer custom ground straps. You can find all battery ground strap options and get the proper custom ground strap solution. To avail of our services, contact us now.

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