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What color goes on what with jumper cables?


Jumper cables, also known as booster cables or jump leads, are an essential tool for jump starting a vehicle with a dead or weak battery. They allow you to transfer electricity from a good battery in another vehicle to the dead battery, providing enough power to start the engine. Using the proper color coding when connecting jumper cables is crucial, as connecting them incorrectly can result in sparks, damage to the vehicles, or even injury. This article will provide a quick overview of how to use jumper cables safely, with an emphasis on following the proper color order.

What are jumper cables?

Jumper cables consist of two thick, specially insulated cables with large clamps on each end. They are designed to handle the high amperage required to start an engine. The cables transfer electricity from the alternator and good battery to the dead battery. This provides the surge of power needed to crank the starter and get the engine running. Once running, the alternator will recharge the formerly dead battery. Jumper cables come in various lengths, typically 10 to 20 feet, to allow positioning two vehicles near each other. The clamps must make tight, secure contact with the battery terminals to prevent arcs, sparks, or overheating.

Why does color order matter?

Using jumper cables in the wrong sequence or connecting the clamps to the wrong terminals can result in electrical arcs, sparks, and potential damage. At best, crossed cables may simply fail to start the vehicle. At worst, it can cause overheating of the batteries and cables, explosions, or damage to the vehicle’s electrical system. The color coding provides a foolproof method to avoid mistakes and safely connect the jumper cables. Think of the color sequence as a reminder of which vehicle and which terminal to connect first, second, third and fourth. Always double check the polarity and cable position before attempting to jump start a battery.

Standard jumper cable color coding

The standard color coding for 4-gauge jumper cables is:

  • Red – Connect first to positive (+) terminal of dead battery
  • Black – Connect second to negative (-) terminal of dead battery
  • Red – Connect third to positive (+) terminal of good battery
  • Black – Connect last to negative terminal of good battery or ground

This sequence ensures that the final connection is as far away from the dead battery as possible. It avoids the risk of sparks near the battery gases that could cause an explosion.

Connecting the cables

Follow these steps when connecting jumper cables:

  1. Position the vehicles within cable reach, but do not allow them to touch.
  2. Turn off both vehicles and set parking brakes.
  3. Pop the hoods and locate the battery terminals in each engine bay.
  4. Identify the positive and negative terminals on each battery.
  5. Attach one red clamp to the positive terminal of the dead battery.
  6. Attach the black clamp to the negative terminal of the dead battery.
  7. Attach the second red clamp to the positive terminal of the good battery.
  8. Attach the last black clamp to the negative terminal of the good battery or a ground such as the engine block or chassis.
  9. Start the vehicle with the good battery and allow it to idle for a few minutes.
  10. Try starting the vehicle with the dead battery. If it fails to start after a few attempts, allow the good battery to continue charging it.
  11. Once the dead battery vehicle is running, remove the cables in the reverse sequence.

Following this step-by-step process while observing the correct color order is crucial for safe and effective jump starts.

Identifying positive and negative terminals

– The positive (+) battery terminal will generally be larger in diameter than the negative (-) terminal.

– The positive terminal may be marked POS, P, + or red. The negative may be marked NEG, N, – or black.

– In some batteries, the positive terminal has a red cover.

– Trace the battery cables. The positive cable is typically red or orange and connects from the positive terminal to the starter motor.

What could go wrong?

Connecting jumper cables incorrectly or in the wrong order can result in:

– Sparks near the battery. This could cause an explosion of the hydrogen gas produced by the battery.

– Electrical arcs that damage the cable insulation and clamps.

– Connecting positive to negative terminals that can instantly drain both batteries, overheat the cables, and potentially destroy electronic components.

– Burns to the hands and face from sparks and hot cables.

– Damage to the charging system if connected backwards.

Safety tips

– Wear eye protection and do not lean over the batteries.

– Avoid touching the clamps together or resting them on the same metal surface.

– Check that the cables are in good condition with no cracks, damage, or corrosion.

– Make sure the vehicles are not touching and that they are in park with the parking brakes set.

– Remove any metal jewelry that could contact the terminals and complete a circuit.

– Keep the cables away from hot or moving parts in the engine bay.

– Have a fire extinguisher on hand in case of sparking or overheating.

When to call a professional

While using jumper cables with the proper color coding is generally safe, some situations require calling for professional roadside assistance:

– You are unsure of the correct procedure, terminal locations, or cable color order.

– The battery is cracked, leaking, or appears severely corroded.

– Jumping the battery fails to start the vehicle after several attempts. This could indicate an underlying electrical issue.

– The cables or terminals feel hot to the touch while jumping.

– You do not have the proper 4-gauge jumper cables in good condition.

– Neither you nor someone else present knows how to safely jump start a dead battery.


Jumper cables are a simple and effective means of jump starting a dead battery when the proper color coding and connection sequence is followed. Always take safety precautions such as eye protection and identifying the battery terminals. Ensure the cables are in good shape and make tight connections with the battery terminals. Follow the steps precisely, beginning with the dead battery’s positive terminal. Finish by connecting the last cable to the good battery’s negative terminal or grounded engine component. With care and attention, jumper cables can safely deliver the surge of power needed to get your vehicle started and on its way again. Knowing the color coding helps avoid mistakes that could result in injury or vehicle damage.

Frequently Asked Questions

What are the standard jumper cable colors?

The standard jumper cable colors are red and black. One red cable connects to the positive (+) terminals on each battery. One black cable connects to the negative (-) terminals.

Does the order matter when connecting jumper cables?

Yes, the order is crucial. You must connect the red cable to the dead battery’s positive terminal first. Then connect the black cable to the dead battery’s negative terminal. The final connection of the last black cable should be as far from the dead battery as possible to avoid sparks.

What happens if you connect the cables wrong?

Connecting the cables incorrectly can cause electrical shorts, sparks near the battery, and potential damage to the charging systems. Cables connected backwards may drain both batteries or cause overheating.

Where do you connect the last jumper cable?

The final cable connects to the negative terminal of the good battery or a grounded engine component like the chassis or engine block. This should be as far from the dead battery as possible.

Can you touch the positive and negative clamps together?

No. Allowing the clamps on the jumper cables to touch or connecting positive and negative terminals will result in a short circuit. This could cause sparks, extreme heat, and damage the batteries and cables.

How long can you leave jumper cables connected?

Leave the jumper cables connected for 3-5 minutes while attempting to start the dead battery vehicle. If it does not start, wait an additional 3-5 minutes before trying again to allow more time for recharging. Remove the cables immediately once the vehicle starts to avoid overcharging the battery.

Should both cars be turned off when jumping?

Yes. Both vehicles should have their engines turned off during the jump starting process to prevent electrical damage. The good battery vehicle can be left running once the cables are properly connected.

Can you jump start a dead battery more than once?

Yes, a dead battery being jumped can be attempted multiple times. Allow 3-5 minutes of charging time from the good battery between starting attempts. If it fails to start after several attempts, there may be an underlying issue.