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How to use jumper cables

Updated March 23, 2017

Jump leads are used to start a vehicle with a dead battery. The jump leads are attached to the dead battery and a fully charged battery in another vehicle. This must be done correctly and in the right order to avoid sparks or a shock. It is also important to disconnect the jump leads in the right order. Once the vehicle with the dead battery is started, drive the vehicle to charge the dead battery.

Determine whether you need jump leads. If you turn the key and your vehicle makes a click, but won't start, you will indeed need jump leads. If the vehicle makes a starting noise and electrical devices such as your lights and radio work, then the battery is not your problem; thus, jump leads will not help.

Unravel the jump leads so that they are straight. Note that each end has two clips: a red clip and a black clip.

Park the vehicle with the fully charged battery next to the vehicle with the dead battery. It is important that the two batteries are close enough so that the jump leads can reach. It is best to park the vehicles with the engines either facing each other or side by side. Raise both bonnets so the engines are exposed.

Attach one of the jump lead red clips to the positive terminal of the dead battery. A "+" sign will indicate which terminal is positive. The positive terminal is also a little bit larger than the negative terminal. You may need to remove a plastic cover on the terminal to attach the red clip. The clip should be attached to the metal part of the terminal nub.

Attach the other red clip to the positive terminal of the fully charged battery. This will also be designated by a "+" sign and the positive terminal will be slightly larger. The clip should be attached to the metal part of the terminal nub.

Locate the black clip next to the red one you just attached to the fully charged battery. Attach this black clip to the negative terminal of the fully charged battery. This will be indicated by a "-" sign on the battery. The clip should be attached to the metal part of the terminal nub.

"Ground" the other black clip to the engine block of the car with the dead battery. You do this by clipping it to any piece of metal on the engine. Don't panic if your jump leads spark a little bit when you do this. If you aren't touching any metal parts, you won't be shocked.

Start the vehicle with the dead battery. It should start right up. If it doesn't, check the connections on your jump leads.

Disconnect the jump leads in reverse order. Remove the black clip on your engine block first followed by the black clip on the charged battery and then the red clip next to it. Finally, remove the red clip on your battery.

Tip

Be sure to drive your vehicle around for 20 to 30 minutes after using jump leads so your battery charges again. If you don't, you might need to use the jump leads again the next time you want to start your car.

Warning

Do not touch any metal parts on the jump leads or batteries at any time during this process. You could get quite a shock if you do. Also avoid touching any powdery substance on the engine. This is battery acid and could burn you. Use a rag to wipe it away instead.

Things You'll Need

  • Jump leads
  • Vehicle with dead battery
  • Vehicle with charged battery
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About the Author

Kent Ninomiya is a veteran journalist with over 23 years experience as a television news anchor, reporter and managing editor. He traveled to more than 100 countries on all seven continents, including Antarctica. Ninomiya holds a Bachelor of Arts in social sciences with emphasis in history, political science and mass communications from the University of California at Berkeley.