5 Symptoms of a Bad Ground Strap (Ground Wire) and How to Replace It

Last Updated on October 7, 2021

The ground strap is the heavy black wire which connects to the car battery’s negative terminal to the chassis of the car. Some other names for the strap include: negative battery cable, ground wire, or ground cable. The ground strap is the foundation of the entire vehicle’s electrical system.

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All of the electrical currents that flow throughout your vehicle goes through this battery ground cable. If you were to have a bad ground strap in your vehicle, then you will have all kinds of electrical problems. These wouldn’t just be minor problems either because it would affect your ability to operate the vehicle altogether.

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Top 5 Symptoms of a Bad Negative Battery Cable

Fortunately, it’s fairly easy to recognize the symptoms of a bad ground strap. The symptoms might start out being minor, but they could progressively get worse if you don’t do anything about the ground wire. Don’t wait until that happens. Take any electrical problems seriously when they occur in your vehicle.

Below are the top 5 faulty engine ground wire symptoms.

#1 – Flickering Lights

high beams not working

If your ground strap is damaged or worn out, the electrical circuit will come across resistance while trying to deliver power to the headlights in front of your vehicle. As a result, you’ll likely notice  your headlights either flickering and/or dimming on a regular basis.

This will not just be a one-time incident as long as your ground strap continues to stay in its current faulty state. In some cases, your ground strap may just be a little bit loose and will require you to tighten it securely. Otherwise, you will need to replace it altogether if it is damaged or worn.

#2 – Low Voltage

battery voltage

If there still appears to be electricity in your vehicle but it seems a bit less powerful than normal, you can conduct a voltage test on your battery. A digital multimeter can be used to measure the amount of voltage coming from your battery terminals.

A reading of 12.6 volts would be within the normal range. But if you have a reading that is under 11.5 volts, it’s probably due to a grounding issue. At that point, you should start your troubleshooting by looking at the ground cable.

#3 – Dead Battery

car battery age

If your car’s battery seems like it just won’t take a charge, don’t automatically assume the battery is bad. Your vehicle’s charging system depends on having a good ground. If the ground wire is bad, then the battery cannot be charged.

Of course, another reason for a dead battery could be issues with your alternator or the wire that connects from the alternator to the battery. But if these parts are in good condition and you still have a dead battery, then chances are a faulty or loose ground strap is the problem.

#4 – Car Won’t Start

There could be a dozen reasons as to why your car won’t start. But if you’ve experienced the first three symptoms on this list beforehand, then it is safe to assume that you’ll soon have problems starting your vehicle.

When the ground strap is bad and you attempt to start your vehicle, you will probably hear a lot of tapping sounds. This is coming from the solenoid of the starter while it is opening and closing repeatedly. That happens because it is not getting enough voltage, again, due to the cable that connects to your battery’s negative terminal.

Read Also: 7 Causes of a Malfunctioning Car Alarm

#5 – Visible Ground Strap Damage

bad ground strap symptoms

The best way to confirm that your ground strap is in bad shape is to visually inspect it yourself. If the ground strap appears to be damaged or worn out just by looking at it, then it is safe to assume you’ll need to replace it.

This is especially the case if you notice the other symptoms mentioned here too. The only thing you can do at this point is to replace the cable with a new one.

If you store your car outside for long periods, there is one culprit of the damage you probably haven’t considered… rodents. Mice and sometimes even squirrels love the safe confines of an engine bay and won’t hesitate to build a nest there. You might want to consider investing in some type of under the hood mouse repellent.

How to Replace a Negative Battery Cable

types of ground wires in car

If you’ve determined that the ground strap is in fact bad, replacement of the cable is the solution. Fortunately, it’s incredibly easy if you follow these simple steps:

1. Identify the negative battery cable (ground strap)

In most cases, the negative cable (or battery terminal cover) will be black while the positive cable (or battery terminal cover) will be red. In addition, the negative terminal will have a minus (–) sign next to it while the positive terminal will have a plus (+) sign.

2. Disconnect the negative cable

Using a wrench (most commonly an 8mm), loosen the bolt that holds the negative cable in place. Once the bolt is loosened, you will need to wiggle the terminal while pulling up at the same time to remove it from the battery post. If the bolt is seized and won’t move, spray some WD-40 on it and let it sit for a few minutes before trying again.

3. Disconnect the positive cable (optional)

Because the other end of the negative cable will likely be out of reach in most engines, the car battery will need to be removed to allow access. To do that, the positive battery cable will also need to be removed. The process is same as above.

4. Remove the battery (optional)

If a bracket is holding the battery in place, you will simply need to unscrew the bolts (usually two) that hold it there. Once done, carefully lift the battery out of the engine bay and set it on the ground.

5. Remove bad ground strap

Follow the negative battery cable to where it attaches to the vehicle. Use a wrench to untighten the bolt that holds the ground strap in place and remove the faulty ground strap.

6. Install new ground strap

Once you confirm the new ground wire has the same time of terminal connectors as the old one and is long enough, follow the instructions above in reverse order to connect the new ground strap and put everything back together again.


56 thoughts on “5 Symptoms of a Bad Ground Strap (Ground Wire) and How to Replace It”

  1. I have a 05 Honda Civic 1.7 Liter have changed almost all electric components that I can think of. Had it running for 30 to 45 mins, jumped in for a test drive put the car in reverse and it spit ànd sputtered then shut off. Only runs when I put a little gas in throttle body. Tries to start back up but just won’t run. Does anyone have any suggestions?? Will ground strap have anything to do with this issue??

  2. My 1992 Pontiac Grand-Am often refuses to start. I just hear a click and see smoke coming from under the hood. I finally saw that the smoke was coming from the chassis ground wire that is connected to the negative battery cable. Could my problem be as simple as just replacing the ground wire?

    • More likely, the ground has a loose connection on the battery or frame rail. Check that first before replacing the ground strap.

  3. I have a 2005 Scion Xb. Dash Lights are flashing. (brake lights is on when parking brake is not engaged, abs is on, check engine is on, ect) There are no codes. VSC and track off are also on. The speedometer is also jumping while this happens. It only does this when the vehicle is moving. If I step on the brakes, normal function resumes (No dash lights). Sometimes if I turn something off it will stop, but it is never the same device. (windshield wipes, ac, ect). The battery is fully charged and the alternator is working correctly.

  4. I overhauled a diesel engine. When it works for like 20mins. And i off the engine it wont start and the engine will be cranked slowly when hot. But when i used 24v battery,it starts working at once. What could be the problem

    • While driving back from Gatwick my Nissan quasqaue seamed time struggle for power then when I pulled in knocked engine off wouldn’t start played with negative battery terminal car started second attempt then drove ok for next 60+ miles any ideas what happened

    • Hi Azeex, I have the same exact problem on a Toyota 1KZ diesel engine. I haven’t been able to solve it for years. Starts fine when cool, cranks extremely slowly when warm/hot. Changed grounds, added extra ground straps, refurbished starter, new battery etc, same problems. Were you ever able to solve it?

  5. Hi there I have a HYUNDI Santa Fe 2004 2.7 V6 the car keeps stopping at random, I have checked all the wiring, cleaned up ground points all over the car, replaced the fuel pump, crank sensor, air control actuator, added a few more ground straps to motor, no codes come up on ecu, not sure what to do now it’s got me beat can anyone help me.

  6. It’s good to know that if your alternator is working fine and you still have a dead battery, then it’s probably a faulty ground strap. Within the last couple of weeks, I have had to jump-start my car twice and don’t know what the deal is. I appreciate the tips and I’ll have to continue my research to see if I need to bring it into a mechanic.

  7. 96 ford mustang 3.8L
    I had an issue where I would turn the ignition and the car would just click and all the power would go off. I would then go wiggle the negative battery terminal connection and that would allow me to start my car. This happened again tonight only this time I couldn’t get the car to turn on. Instead I have a ticking noise in my trunk. I hooked up a booster to it and tried to start it that way and i got a bunch of ticks in a row(probably the starter not getting enough of the juice?) You think this is a ground issue? Also why the ticking in the trunk?

    • Assuming your battery is good, check for corrosion around the terminals and ground strap and confirm everything is tightened to make sure you have a proper connection.

    • Deiver side kick panel there’s a harness in the mustang that come loose I think it’s a 10mm boot that just needs tightened

  8. I have a 2009 Silverado and every now and then I start my truck and go down the road and I lose power, gauges go haywire, door locks go up and down and lights flicker. What do you think is the cause? Anyone ever have this problem?

    • Definitely an electrical problem. Likely a bad ground, damaged wire, or poor connection somewhere. Unfortunately, these are tricky and often time consuming to find the culprit. Start at the battery cables.

    • Put a new Speaker in your Driver Side Door and that Will Fix your Problem with the Silverado! Chevy is Notorious for Running everything through the Head Unit/ Stereo and the Driver Side Door Speaker! Water gets in behind the Glass and Drips down and I HAVE NO IDEA WHY THESE GENIUS ENGINEERS WOULD MOUNT THE DOOR SPEAKER WITH THE TERMINALS FACING STRAIGHT UP TOWARD WHERE THE WATER DRIPS DOWN BUT THEY DO! IT HAPPENED SO MANY TIMES IN MY SILVERADO THAT I ENDED UP JUST BUYING MARINE/BOAT SPEAKERS THAT WERE WATERPROOF! I HAVE SOLD THE TRUCK NOW BUT AFTER I DID THAT I HAD NO PROBLEMS WITH IT AT ALL!!!!!

  9. I got a 2004 dodge durango it wont turn over but starter is getting power cause i can hear wat sounds lime a thud coming from starter when i turn key. I just replaced starter but its doing same thing old one was. Could it b a bad groung

  10. I have a 2007 Honda Odyssey. I believe I have some kind of grounding issue. I have funky things go on like window will go down on it’s own Nd can’t get it to go up. I will lock the tje windows with the push button on the driver door and tje back window will go down. I shut the car off Nd when I take the key out the same passenger side back window goes down. Dash lights flicker when car is off. Alarm goes off in the middle of the night. Battery usually dead in the morning and it’s a new battery. Its always worse when it rains.

  11. I have a 09 pontiac g6 replaced the engine and transmission but sometimes when I start my car it would mildly shake and say engine reduce and I turn my car off and pop the hood and wiggle my battery cables and start it back up it runs normal so not sure what that could be??

    • If wiggling your battery cables fixes the issue, you may have a poor connection at the battery or corroded terminals. Buy a battery terminal cleaner if you don’t have one and make sure to clean off any corrosion. Corrosion will appear white from battery acid, or could also look like rust. Make sure to disconnect the battery at both ends when you do this. Disconnect the negative terminal first.

      When you reconnect the battery, make sure both terminals are nice and tight. Be sure you don’t over tighten them though; I know a guy who stripped his battery by over tightening the battery bolts. Just make sure they’re snug.

  12. I bought and installed a new battery 3 days ago after my car wouldn’t start. The new battery worked just fine these past two days. However, my car wouldn’t start today and started making a clicking noise when I turned the key in the ignition. I tried readjusting the terminals to ensure they are secure and they were. Could this be a bad ground wire or possibly alternator ?

    • Make sure you clean any corrosion on the battery terminals. I recently had a brand new battery fail to start the car because the terminals were so corroded, despite having enough juice to illuminate the dash and run the accessories.

      Do a visual inspection of the starter ground and any other ground straps in the engine bay to make sure the grounds aren’t loose, broken, or corroded.

      If your battery actually died within 3 days, I suspect there is a parasitic draw. You should be able to locate it using a multimeter if this is the case.

  13. I have an 06 bmw x5 and all the lights are on, on the dash. the driver door wont unlock electronically and the headlights lights flicker, battery good and the ground cable often feels hot. do you guys think this is the ground?

    • It sounds like you may have a bad ground or electrical short somewhere. Check to make sure your battery terminals are tight and free of corrosion. Corrosion creates resistance, and resistance creates heat. If your terminals look like you’re trying to grow a Chia pet, perhaps that could be the issue.

      If it’s getting hot, I wouldn’t drive it until you can pinpoint the problem. You don’t want to start an engine fire.

  14. My 2004 Mustang V6 recently had both cables replaced with the Motorcraft set, a new alternator, starter & battery & I am still have a strange battery related issue. When I go to turn it over (intermittently) it will attempt to start then abruptly go dead. Upon trying to restart I get no response. If I touch the negative battery cable on the battery it will start back up. It is tightened as tight as it will go & does not move so I am not sure why it is loosing ground there unless it is damaged at the terminal under the insulation. Any advise on how to fix this would be appreciated as this will be a 17 year olds first car & I would like it not be breaking all the time.

    • It sounds like you’re on the right track. One thing you could try is to disconnect both battery cables, remove the battery, then grab a test light. Connect the test light to each battery cable, then start wiggling the negative battery cable just as you described. If the light flickers or goes out, there’s a bad connection in there somewhere. You should be able to move the leads of your battery light around to different parts of the wiring harness to pinpoint the exact section of wiring that’s gone bad.

      While you’re in there, make sure the ground strap is tight where the negative battery cable grounds to the chassis.

  15. i have a 1989 talbot express campervan that starts ok with a fully charged battery but if i leave it a few days the battery just drains, i have checked all lights etc but nothing has been left on by mistake, what would cause battery to drain so quick

    • It sounds like you have a parasitic draw from some accessory that is consuming power while the vehicle is off. Double check that you haven’t left any lights on (even the overhead interior light will drain the battery eventually). If you have any aftermarket components like a head unit, I would start at those.

      You could grab a multimeter and start testing which components have a draw while the vehicle is off that shouldn’t. Do a quick google for “parasitic draw test” and you will find some great instructional videos on the subject.

    • Sounds like a poor electrical connection. In your driveway while the car is idling, you can try wiggling parts of the wiring harness to see if you can get it to stall on you. Start at the battery and also wiggle the wiring harness around the ECU if you can get to it.

  16. im having an issue with battery light on my passat b7 2011 bluemotion 2.0 TDI 103kw. On dashbaord battery light does blink ( from very light red to completly red ). Also if do switch to turn right battery and turn icon blink both same time. Same is with back breaks ( P ) if i turn on battery icon disapear and P letter lights on release breaks and its back to battery light. I was thinking its right side back grounds but i kinda found all at engine section ( one in corner below battery was broken ) did screw new hole and made it. Rest ones i found did cleaned if found any rust.Car wasnt used for while so AGM battery was dead i replaced with not agm one. Also its charging 15.05. Also then try turn it on push key and its turns on like after 3 or 5 seconds.

      • I meant that battery light is on atm but its blinking not always glow fully red. And if i use turn to right battery light also start blinking like turn to right arrow both same same time. Na if i could i would im kinda not from USA wanted hear opinion at first place and my english not my first language sorry

        • If the battery light is blinking at the same time as the turn signal, it sounds like an electrical issue that is shorting out the battery light indicator. You will have to do some troubleshooting with a multimeter to figure out where the problem is.

          Take a look at the turn signal circuit and battery light indicator circuit. See if they share a wiring harness or have a common ground. It could be an exposed wire where the insulation rubbed away, or perhaps a bad ground.

  17. Well if i could i would but sadly im not from usa. I do have some issue about pretty sure ground wire. But im not quite sure what is wrong since i almost find them all and did clean if found any rust. Anyhow i still have battery light on on my dash. Its blinking from very light red, to fully red ( sometimes its disapear and light up next second). Also if i use turn to right , turn right arrow and battery light blink both same time. What else could be wrong ?

  18. I have a 2009 Mazda 5, over the last few weeks I occasionally loose power
    steering, but once I turn the wheel it returns. I also occasionally stall when idling
    (such as at a traffic light)
    The Mazda dealer stated that my issue was a weak battery and wanted to replace it but when I brought the battery to an auto parts store the battery tested fine but they did notice that the negative cable was loose. Could this really be an issue with my battery?

    • A loose negative cable could certainly cause issues. I had a hard time getting my car started with a loose cable, even though there was no corrosion. I would get that addressed and see if it fixes the problem before dumping too much money into it.

  19. 08 corolla runs fine but randomly has no electrical power at all in the mourning when i go to start it smh. Slamming my door hard returns power and i can start it but not always. I made sure terminals are clean and tight. Battery alternator and spark plugs are brand new like 2 months old. What could this be besides an ignition relay or fuse box issue maybe?? O just removed the negative terminal ground cable and cleaned it put it back on. Car has been fine since then but it was just yesterday so I’m worried it will happen again. Any help??? Much appreciated

    • I’m not sure. I would test the battery and the alternator to make sure they are both still good, especially if your battery is old. Maybe cleaning the terminals was all it needed.

      • My Corolla 07 has the same problem .
        randomly 0 power after start up or power goes off ones the ignition key is inserted.
        I get out and touch the battery power gets back on and Car starts and runs normal .Recently its happening more frequently.
        What could be to culprit?

  20. i have a 2010 Honda Accord EX-L 4 cylinder. The center brake light stays on when the head lights are on. The cruise will not engage with the head lights on. With the headlights off, all works fine. Is this a ground problem and where should I look? Note: with the the brake light bulbs pulled out and the center bulb in, it still comes on when the head lights are on.

    • It does sound like a ground problem, or possibly an electrical short. I am not exactly sure where to look on that model, but if you grab a wiring diagram for your year, make, and model and follow the brake and headlight circuits, you should be able to narrow it down pretty quickly. Good luck on your search.

  21. I can beat all of these problems
    I installed a one wire alternator in my 69 Mach1 mustang
    When I went to put the negative battery terminal on the negative battery post
    The battery terminal stuck to the battery post like a very strong magnet
    I quickly pulled them apart
    I looked and part of the negative battery posit was melted, gone
    Also smoke was coming out of my trunk, drivers side light
    Lots of smoke
    I contacted painless wiring, summit, tuff stuff who made the alternator. No one can answer why.
    Never happened with the old alternator
    My opinion or guess is the new alternator had a short in it. Just guessing.
    I returned that alternator and got another one. Haven’t installed it because
    no one can tell me how to wire up the new alternator with my painless wiring harness
    I have a black/yellow wire has alternator written on it
    But the instructions say to just connect the two wire pigtail green wire to the voltage regulator field wire and don’t use the pigtail yellow wire
    Don’t put anything on S position on the voltage regulator
    I have a 22 circuit wiring harness from painless wiring fir a 351 Ford engine
    #915 black/ yellow wire coming from the headlight section to the fuse block
    So 3 questions
    Why did the battery terminal weld itself to the post?
    Why was there smoke coming out of the taillight drivers side
    How do I wire up the alternator and voltage regulator to my painless harness

    • 1. I don’t know, it sounds like the polarity was reversed somewhere and you ended up hooking a positive cable to a negative terminal (or vice versa). This can happen for instance if you jump a car wrong and hook up the jumper cables to the wrong posts on one vehicle.
      2. Do you have any fuses in that car? I’m guessing something shorted out in the taillight. By putting way too much current through the circuit, the wire in the taillight would get very hot and melt. This could very easily start a fire, but it sounds like you got lucky.
      3. I can’t really answer this question without knowing more about the components you’re using, but judging by the result I think you would be better off taking the car to a professional to have them install the new alternator. There’s no shame in doing this, and perhaps they can tell you more about what went wrong.


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