Duramax Ground Issues: Main Symptoms and Best Solutions

Although many issues could give you headaches, we believe that we can all agree that electrical problems are some of the most annoying out there. Not only do they cause the vehicle to behave like it has been possessed, but they also take a lot of time to diagnose.

Ground problems highlights

• Level of urgency:high
• DIY inspection:possible
• DIY repairs:possible
• Can you drive?usually, no
• Price of repairs:$0 - $150
• If ignored:low voltage, car glitching heavily
• Ways to fix:clean ground contacts, find a good car electrician

What are ground points?

A ground point is a connection fitted to the case or the body of a vehicle and its purpose is to protect certain electrical circuits against transient voltage and voltage surges. These components usually look like studs or lugs on the component's casing or on the bodywork of the vehicle. They are extremely important since their duty is to protect vital electrical components from frying that could be caused by circuit problems or even by a lightning strike.

To fully understand their importance, simply think about the fact that most electrical components in a vehicle do not even work without a good grounding point.

Faulty ground points symptoms

As with pretty much all electrical problems, bad ground points could make the car behave in a very strange manner and at first, it might seem a little bit difficult to tell what exactly is wrong, but if you follow a few important steps, it shouldn't be so hard to identify what the problem is. Here are a few things that could indicate you have bad ground:

• Warning lights in the instrument cluster

Let's say one day you go to your car, start it, and then you notice that the instrument cluster looks like a Christmas tree, even though everything seemed to work fine. This could be an indicator of a bad grounding point. Keep in mind that this could also be caused by a faulty battery, but before replacing it, you should definitely check the grounds.

• Flickering or dim lights

This is something you will most probably notice at night, but you probably won't miss it. Even though at first it might seem that your eyesight has gone bad, don't panic. Flickering lights (both inside and outside) are one of the most common signs of a bad ground point.

This is an issue that can also be caused by a bad alternator, that's why it's important to eliminate the issues one by one, to avoid replacing working components.

• Difficult starting

If for some time the Duramax has been more and more difficult to get going, it's time to check the ground points. Bad grounds will always make a vehicle more difficult to start.

• Battery drainage

You are 100% sure that you haven't forgotten to turn off the headlights and you haven't left anything plugged into the car's 12V power outlet, yet you still come back every morning to a dead battery. Time to check those ground points.

• Strange radio noises

Those tunes you've been listening to seem to sound a little bit different than what you were used to. Bad ground points can interfere with the radio and they will cause all sorts of strange noises to come through the speakers.

• Intermittent sensor failures

Sometimes they work just fine and sometimes they don't. Frustrating, right? While this could also mean that the sensors themselves are going bad, we recommend you check the grounds before replacing anything else.

• Rough running of the engine

Although it might seem like there is no actual link between the grounds and the running of the engine, it's not the case. If you think about it, important components such as the fuel pump are powered by the vehicle's electrical system and any problems in that department will almost certainly affect how the engine runs. So, if you think it shakes more than it should or if it lacks power, it would be a good idea to check the ground.

How to fix bad ground points?

If you decide to try and fix the issues yourself, we recommend you always remove the negative terminal from the vehicle's battery before doing any other work related to the electrical system of the car, to avoid damaging important components, such as the ECU or various other modules.

Usually, bad ground points are caused by loose or corroded wires, which should be quite easy to notice. The connections themselves can also suffer from such issues, so check them as well. If the problems have only started after installing an electrical component, you should double-check the way it was installed, since that might have had something to do with the way the electrical system of the vehicle works.

A very important tool that you shouldn't start troubleshooting without is the multimeter. This is a great device that will help you a lot and it's also useful when you want to check things such as the charge of the battery, or if the alternator is performing how it should.

For pretty much all vehicles out there, including everything equipped with a Duramax engine, there should be electrical diagrams available on the internet or in service manuals, which will tell you exactly where are all the ground points of the car you are working on.

If they are not physically damaged, many times you can solve the problems by simply cleaning these grounding points. Using a very fine piece of sandpaper, you should try cleaning both the ground strap connection and the actual point to where it bolts to. With age, this seems to affect quite a lot of vehicles.

Sometimes, the connections might not be corroded, yet they still cause issues. Another thing you could try would be to simply tighten them. With time, because of vibrations, they might become loose, which will almost certainly cause problems.

If these connections are physically damaged, you would be better off simply replacing them with new ones, since they are usually widely available and not very expensive.

Should you decide to leave this issue to a specialist, do not expect the service bill to be cheap, since sometimes the problem might be something that took a lot more time to find than you might have thought, and since most shops out there charge you by hours worked, it might have taken the specialist many of them to find what the actual problem was, even though the fix itself wasn't particularly difficult.

How to prevent this issue?

When it comes to preventing issues, there's little you can do, since these are not components that most owners usually interfere with. With age, most vehicles could develop ground issues, but happily, they are not impossible to repair.

One thing we recommend you to check regularly is water ingress. This could cause premature corrosion, which is one of the main causes of ground terminal damage. Therefore, we recommend you check all the seals and water drains of the car from time to time, to make sure that there is no water where it shouldn't be.

Another important thing to keep in mind is to avoid having aftermarket electronic devices fitted improperly to your vehicle since they can often cause more harm than good. If you are not sure how to install them, it would be best to ask for specialist help. It's always better to pay at that time than having to pay five times more just for repairs in the future.

Is it safe to drive like this?

This is something very debatable since it depends a lot on what the actual issue is. If we're talking about strange radio noises or something that doesn't affect the way the vehicle drivers, it should be OK to drive the car like this for a short period, or at least until you find the time to fix it.

If the issue affects the way the engine is running, or if you have found yourself in the nasty situation of your car simply not starting anymore or cutting out while driving, then you should definitely avoid driving and have the issue fixed as soon as possible.

Final thoughts

Bad ground points, surprisingly, are problems that are overlooked by many people out there, yet they are the cause of so many electrical issues. They are not always the root of your problems, but many times, simply checking or repairing them could save you so much money. Imagine if you would have replaced expensive components such as the ECU when the actual problem was just a loose ground point.