Can Welding on a Car Cause Damage? 5 Tips Welding Your Ride

For transparency, we would like you to know that as an Amazon Associate we earn from qualifying purchases made on our website through links and ads.

You may want to either upgrade or fix the body or components of your car. One of the best ways to address metal fixes and attach metal components is welding. The only problem is that using a welding torch requires putting electricity through the metal of the car. You might balk at this prospect, but there are some techniques you can use to do it.

Can welding on a car cause damage? Yes. Welding on your car requires you to put electricity through the metal of the vehicle. Since the car’s metal is attached to the electronics of the vehicle, you can end up frying the electronics in the car.

Can Welding on a Car Cause Damage? 5 Tips Welding Your Ride

Even though you may end up frying the electronics in the car, there are precautions that you can take to weld safely on your vehicle without causing damage.

Read on to learn how to limit the amount of juice going through your car electronics while you weld making it safer to weld on your car without damage.

Why Does Welding on a Car Cause Damage?

When welding on metal, you need to create an electric current from the welding torch to the metal you are welding.

This electrical current goes through all of the metal you are working on. If you have electronics connected to the metal you are welding, these electronics also receive the electric current.

This electric current could potentially damage the inner workings of these electronics.

When we are talking about electronics in your car, we don’t only mean your radio.

why does welding on a car cause damage?  it could hurt the radio, but that is not the real problem

Radios can be replaced and are relatively inexpensive.

The most vital part of contemporary cars is the computer that runs the firing of the pistons and controls and manages the running of the engine known as the engine control unit or ECU.

Welding and creating an electrical current through the ECU can damage the computer irreparably. This computer is essential to your car functioning, and you would not be able to drive if the ECU becomes damaged or destroyed.

Protecting the ECU is necessary if you are going to try to weld on your vehicle.

How to Protect the ECU While Welding on Your Car

The ECU needs battery power or voltage to run correctly. However, the ECU is only designed for a smaller amount of energy that the car battery can deliver.

People also read:  4 Ways to Store Welding Rods Effectively and Combat Moisture

When you weld, you are using a much higher voltage. So, if the welding power of electrical voltage reaches the ECU, it causes damage.

Below are the step-by-step directions and reasons for limiting exposure of the welding voltage to the ECU:

  1. Remove the car battery negative terminal: The battery of your car has two terminals (usually a red and black one). The negative one needs to be loosened with a screwdriver and removed from the battery. Removing this terminal is done to reduce overvoltages when the electricity of the car is flowing through the battery.
  2. Ground the area you are working on.  Using something like a welder’s earth grounder helps.  Attaching the grounder carefully to the metal you are welding helps dissipate voltage away from the car and into the ground. This dissipation keeps excess energy away from the car’s ECU. Some of the best grounding tools are:
    • Hobart 770031 400-Amp T-Style Ground Clamp Brass: This brass welders grounding clam is an excellent addition to your welding work. The strong spring in the clamp can hold on securely, and the t-style is always a firm hold on most surfaces. This clamp pulls away 400 amps of electricity, which would be more than enough for your work with an ECU if coupled with at least two more clamps.
  • HITBOX G Ground Welding Earth Clamp 0.75kg Full Cooper 400A High Standard Solid Brass Earth Clamp for Industrial Use. The benefit of this welder’s clamp for grounding is that it can be tightened down to be placed in any position for any surface, and it won’t slip off. This clamp pulls away 400 amps from the metal being worked on.
  • Welding Ground Clamp 500A Electroplated Welding Earth Clip: This welding Earth clamp is a sturdy wired clip with up to 500 amps control. The electroplated clamp and rubber handle make this a safe clamp to hold and clamp when done, even with residual energy in the metal you were working on.
  1. Disconnect vital electronics: Even with the battery disconnected, there could be residual energy in the parallel circuits. This means critical electronics like airbags and even the ECU. The electrical voltage added by the welding and the remaining power left in the car’s circuitry will probably not burn up the electronics but could trigger the airbags.
  2. To disconnect airbag connectors, follow these steps:
    1. Determine where the airbag module is: There are several places that the airbag regulator module could be placed in your car, such as:
      1. On the floor beneath the radio
      2. Under the carpet below the passenger seat
      3. Under the carpet under the driver’s seat
      4. Under the center console
    2. Find the SRS computer module: The SRS is usually located under the center console and in between the two front seats. It could also be possible under the driver’s seat or the center dashboard.
    3. Find and disconnect the positive battery cable: The positive battery cable is the other battery cable with the ‘+’ symbol. Wait a few minutes for the residual charge in the circuits to subside.
    4. Find and unplug the airbag control module: The airbag control module is a harness, which is a plastic box with wiring plugs coming off of it. Unplugging this stops the airbags from firing.
  3. Disconnect the ECU: The ECU is what you are trying to protect in the car when you are welding. If you feel that not enough is done to preserve this vital piece of your car’s engine, you can fully detach it from the car and get it out of harm’s way. The steps below detail how to remove the ECU from the injury of being damaged while welding:
    1. Make sure the battery negative terminal is disconnected: The battery of the car should be divided on the negative side.
    2. Remove the panel where the ECU is located: Most often the ECU is located under the glove box on the passenger side of the car. Open this panel to access the ECU.
    3. Unplug ECU: The ECU is silver and can be removed by loosening the bolts that secure the vehicle with a socket wrench. Once loosened, the ECU can safely be removed from the car.
People also read:  Can You Use Medical Oxygen For Welding?

In Conclusion

Welding on your automobile can severely damage the electronic components in the car and even make your airbags fire. To avoid damaging the vital components of the car, such as the ECU.  You should ideally weld on a separate surface, if at all possible. 

If you can follow these simple guidelines, you can protect the essential electronic components on your car.  Best yet, you will be able to do the bodywork that you need to get done. After all, if you are beautifying your car with some welding work, you want to be able to drive it when you’re done!



Hello, I'm Ben and welding has been a great outlet for me creatively for over 5 years now.

Recent Posts