If you hook jumper cables up wrong, the car will not start. The engine will not turn over and the lights will not come on. You may hear a clicking noise from the engine compartment.
If you hook up jumper cables wrong, one of two things can happen. Either nothing will happen, or you could cause serious damage to your car.
If you connect the positive cable to the negative terminal and vice versa, nothing will happen.
The reason for this is because the current will cancel itself out and no power will be able to flow through.
However, if you connect the positive cable to the positive terminal and the negative cable to the negative terminal, then you’ll create a circuit. This means that current will flow from one battery through your car’s electrical system and back into the other battery.
Depending on how long you leave the cables hooked up like this, you could potentially overheat and damage your car’s electrical system beyond repair. So it’s definitely not something you want to do!
Connecting Jumper Cables Backwards? Here's What Could Go Wrong!
Accidentally Connected Positive to Negative Battery
If you accidentally connect the positive terminal of your battery to the negative terminal, don’t panic! This is a common mistake that can be easily fixed. First, disconnect the negative cable from the battery.
Next, use a clean cloth or paper towel to clean the terminals. Finally, reconnect the positive cable to the positive terminal and the negative cable to the negative terminal.

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What Happens If You Hook Battery Cables Up Wrong?
If you connect the negative (-) cable to the positive (+) terminal and vice versa, one of two things will happen. If the battery is old and corroded, then probably nothing will happen. If the battery is new or in good condition, then a spark will occur and you could potentially fry your electrical system.
So make sure you always connect the negative cable to the negative terminal and the positive cable to the positive terminal!
What Happens When You Put Jump Leads on the Wrong Way?
When you put jump leads on the wrong way, the polarity is reversed and the electrical current flows in the wrong direction. This can damage the electronics in your car, as well as causing a spark that could start a fire. It’s important to make sure that you connect the jump leads correctly, so that the electrical current flows in the right direction and doesn’t cause any damage.
Is There a Wrong Way to Connect Jumper Cables?
You might be surprised to learn that there is a wrong way to connect jumper cables. If you connect the cables incorrectly, you could cause damage to your car’s electrical system. Here’s what you need to know to avoid making this mistake:
The first thing you need to do is identify the positive and negative terminals on your car battery. The positive terminal will usually be marked with a “+” sign, while the negative terminal will be marked with a “-” sign. Once you’ve located the correct terminals, attach one end of the red jumper cable to the positive terminal on your battery.
Then, attach the other end of the red cable to the positive terminal on the donor battery.
Next, take the black jumper cable and attach one end to the negative terminal on the donor battery. Finally, attach the other end of the black cable to an unpainted metal surface on your car – not onto the negative terminal of your own battery.
This will help ground your car and protect it from any potential electrical problems.
That’s all there is to it! Just remember to disconnect the cables in reverse order – starting with the black cable from the ground surface, then followed by both red cables from their respective batteries.
What Happens If You Mix Positive And Negative Jumper Cables?
If you mix positive and negative jumper cables, the result will be a very dangerous situation. The sparks produced when the cables touch can easily ignite any flammable materials nearby, and the electrical current running through the cables can electrocute anyone who touches them. In short, it’s best to avoid mixing up your jumper cables!
Conclusion
If you hook jumper cables up wrong, the car won’t start and you’ll be stuck.