How to jump your vehicle with jumper cables: A step by step guide
Updated: Feb 8
If your car won't start, chances are you'll need to use jumper cables to get it started. Jumping your vehicle battery with jumper cables can be a lifesaver in an emergency. Like fixing a flat, jumping your car isn’t something that’s done regularly and never at a convenient time. By following a few simple steps, it doesn’t take long to jump-start a car. You can be back on the road in a matter of minutes.
Jump-starting a vehicle requires jumper cables to connect the dead battery in your car to a fully charged battery in another vehicle. It’s a great idea to keep a good set of cables along with other roadside emergency equipment in the trunk of your car. If you’re not sure what you need to keep in your car for emergencies, check out “Vehicle Emergency Checklist: What You Should Always Carry in your Car or Truck”.
Before you begin, make sure you have all of the following items: jumper cables, an additional running vehicle, and a clear work area. You should consider all safety risks before performing any basic maintenance or repair on your car. Take a moment to read the manual of your car. Some vehicles require extra steps in order to have a successful jump. If you’re unsure of what to do, contact Danny’s Automotive Service for advice.
When you handle the jumper cables, be aware that their function is to transmit electrical current from one car to another. Once one end of the jumper cables is connected to a car, do not touch the metal clamps to anything but the appropriate target. It’s also recommended that you wear a pair of protective glasses in case sparks go flying into the air.
Step one: Locate the battery
The first thing you'll need to do is find your car's battery. On most cars, this is located under the hood or in the trunk.
Open the hood to both cars and locate the batteries (refer to the owner’s manual for battery location) and battery terminals. Usually, the two terminals on each battery will be covered in red or black, with a + or – sign on top.
Look at the batteries and make sure that you can identify which is positive, and which is negative. This distinction is crucial to the success of your jump.
If the battery terminals are dirty, wipe them off with a rag or wire brush. If the battery terminals are severely corroded, follow our guide of How to Clean a Car Battery.
Step two: Get everything situated
Park the functioning car so that the vehicles face each other, preferably only about 18 inches apart, but never touching each other. For automatic transmission cars, put the vehicle in park; for a manual transmission, set the vehicle to neutral.
Set the parking brakes on both, so neither car moves unexpectedly.
Step three: Prepare your vehicles
Both cars should be turned off, with keys removed.
Set down the jumper cables on the ground, making sure the clamps do not touch each other.
Step four: Connect the cables
Attach the red, positive cable clamp to the positive (+) battery terminal of the dead battery. You want a solid connection to the battery terminal, which may require some initial wiggling of the clamps.
Attach the red, positive cable clamp on the other side of the jumper cables to the functioning vehicle’s positive (+) battery terminal.
Connect the black, negative cable clamp to the working battery’s negative (-) battery terminal.
Walk over to the car with the dead battery. Do not connect the black, negative cable clamp to the dead battery. Instead, attach that clamp to an unpainted, metal part of the car such as a shiny, clean nut on the engine block. This will help ensure a safe jump.
Now you are ready to attempt the jump-start. Follow the instructions below to find out how and how long to charge your car’s dead battery:
Step five: Start the working vehicle
Wait a minute or so. Depending on the age of the battery and how long since it died, you may need to let the car run for a minute or two to get the jump to work.
Try starting the dead car. If the car does not start, allow the working vehicle to charge the battery for an additional minute or two before attempting again.
In some instances, slightly revving the engine of the working car while charging the dead battery may help.
Step six: Disconnecting the jumper cables
Once the dead car is running, you may disconnect the jumper cables, starting with the black, negative cable clamps. Do not let the clamps touch each other while any part of the cables is still attached to a car.
Step seven: Ensure the battery will hold a charge
Now, take a short drive. This will allow the battery to build up a charge. This driving allows the vehicle’s alternator to charge the battery and ensures that your vehicle does not die again once you turn it off.
If problems persist, read through What If My Car Battery Won't Hold a Charge? to diagnose the issue further.
If the Jump-Start Fails
If the jump fails to start your car after a few short attempts, or if the car starts but then dies again, you have some other issues you need to address. Most batteries are rated to last 4-6 years. If your battery is old, you may need to replace it. If the battery should be working well, you should consider other possible problems with other components, including:
corroded battery terminals - How To Clean Your Car Battery
When you do not know what is wrong, your best bet is to take the car in to your local Auto repair shop for service. Many centers like Danny’s Auto conveniently offer free battery inspections and diagnostic scans and can help you understand your vehicle’s issues.
Dealing with a dead car battery is a pain. Luckily, getting your car working again is not terribly difficult. By following these instructions, using your jumper cables sensibly, practicing safety and addressing other potential concerns, your car will run better, be safer, and last longer. There are preventative actions that anyone can take to extend the life of their battery. Check out How to Prevent your Vehicle Battery from Dying to get a sense of the regular maintenance it will take.
For professional advice and assistance, talk to your local mechanic at Danny’s Automotive Services.