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HomeTips & GuidesWhat Cable to Connect First On A Car Battery: A Guide Into Connecting & Disconnecting Your Car Battery

What Cable to Connect First On A Car Battery: A Guide Into Connecting & Disconnecting Your Car Battery

What Cable to Connect First On A Car Battery? When connecting or disconnecting a car battery, there are two positive terminals to pay attention to.

The problem is it’s easy to get the order of disconnecting and connecting terminals wrong when hooking jumping cables to jumpstart your car or replacing your car battery. 

Here’s a guide to what cable to connect first on a car battery.

Table of Contents

How do you know your car battery is dead?

You’ve tried turning the ignition key, and nothing happens. Usually, your first suspect is the car battery. However, if the car attempts to start and then dies, the problem may originate from something else, such as the belt or the alternator

Below are some reasons for a car battery dying:

  • Cold weather
  • Leaving the car lights on for extended periods
  • The battery was dysfunctional or old 

The solution is to have an expert check your car battery and advise you accordingly.  

Check the availability of your car battery

(Check the availability of your car battery)

What Cable to Connect First On A Car Battery:How to hook up jumper cables, and how to jump-start a car

Jump-starting a battery provides a short-term remedy to your vehicle not starting. It helps you start your car to drive to a mechanic to establish and fix the issue.

Here’s how to hook up jumper cables to jump-start your car with the help of another car.

  • First, park the cars close to each other. The idea is so that you can connect the jumper cables. However, ensure that no parts of the cars’ parts are touching each other to prevent the flow of electric current. 
  • Then, identify the location of each car’s battery. Usually, most cars have their batteries near the engine. 
  • Next, power both cars in park mode before beginning the jumper process. 
  • Now identify each car’s positive and negative terminals and attach the jumper cables to the respective terminals beginning with the positives. So, hook the positive cables (red) to the positive terminals and the negatives (black) to the negative terminal. 
Jumper cables attached to terminals

( Jumper cables attached to terminals)

Now follow this simple and safe process when attaching jumper cables:

  • Attach one positive jumper cable clamp to the dead battery’s positive terminal and the second positive clamp to the positive terminal of the working battery.
  • Attach one negative clamp (black) to the working battery’s negative terminal and the other clamp of the jumper cable to the dead battery car’s unpainted piece of stationary metal.
  • A word of caution. Do not attach the clamp to the dead battery’s negative terminal. Otherwise, you increase the risk of fire, or an explosion should the jump-starting process fail to go as planned. 
  • Next, turn on the car with the live battery to start charging the dead battery. Note some cars will start immediately, while others need more battery charge. 
  • Let the live battery car’s engine run for some time to allow a flow of electric current to the dead battery. 
  • Try to start the car with the dead battery’s engine and hold onto the key for a few seconds. The engine should spring into life. 
Car battery located next to the engine

(Car battery located next to the engine)

Note that driving the car will help recharge the battery further.

Your last step is disconnecting the jumper cables if the car starts successfully. To do that, perform the process of connecting the jumper cables in reverse order.

Remember to avoid allowing the wires to come into contact with anything until you disconnect them to prevent the flow of electric currents to unintended parts. 

Here’s a simple and safe way of disconnecting the cables:

  • Begin by disconnecting the negative jumper cables from the terminal that received the current.
  • Disconnect the clamp attached to the working battery’s negative terminal
  • Disconnect the clamp attached to the working battery’s positive terminal 
  • Disconnect the positive clamp that you attached to the car with the dead battery 

You’ve disassembled your jump-start cables successfully! But what if jump-starting didn’t work? Then it means there’s a bigger underlying issue. Having a mechanic examine your car for further diagnosis is important if that’s the case. 

How Do You Jump A Car Battery Without A Second Car?

You can use a portable starter, jump box, or battery pack instead of a second car to jump-start your car. Almost every portable jump starter permanently connects two cables (positive and negative) to the device.

Begin by hooking the positive cable of the jumper box to the dead battery’s positive terminals and the negative cable (black) to the battery’s negative terminal. Then, power the jump starter. 

Next, try to start the vehicle and remove the cables once it starts or allow it to idle for a couple of minutes for the battery to recharge. The engine will turn on if the jump-start is successful. 

What Cable to Connect First On A Car Battery:How to Remove the Old Batteries

Begin by disconnecting the cable from the negative terminal with the (-) symbol. Next, disconnect the positive terminal indicated with a red sheath and a (+) sign. 

What Cable to Connect First On A Car Battery: How to Install the New Batteries

First, inspect the car’s two system connectors and cables before installing a new battery. The presence of rust hinders the cables’ efficiency. Therefore, remove the rust by using a baking soda solution and brush.

Next, connect the positive terminal first when installing your car battery. The negative terminal comes second when installing a new battery because you connect it to the grounded chassis of your car. 

Connecting the negative terminal first will likely create a circuit between the chassis and the battery’s negative terminal. The resultant circuit may damage the electrical system or your car’s battery. 

Test car batteries

(Test car batteries)


The guide has helped you learn the do’s and don’ts when jump-starting your car battery. If your car doesn’t start, follow the above steps to jump-start your vehicle.

A portable jump starter might be helpful depending on your vehicle’s condition.

Hi I am Christa, sales manager of Cloom.

I have extensive expertise and experience in wiring harnesses and I believe I can help you.

And we have a very professional technical team who can clearly understand the customer’s needs and give professional suggestions and solutions after receiving the drawings.

If you also have wiring harness needs, please send me the drawing so that we can give you our quote and start our business.

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