Reasons Why Your Jumper Cables Are Smoking Hot Or Melting

Want to kickstart your dead car battery? The first thing you would look for is a jumper cable. Jumper cables are used to jump-start a vehicle when the batteries go down by connecting them to another car’s battery. But what if the jumper cables start smoking or melting suddenly? 

Wrong cable connection is the primary culprit of jumper cables getting hot and melting. If you connect the cables to the wrong terminal, the jumper cables become extremely hot, which causes the rubber and plastic insulators to get overheated and start melting. 

Loose connections, damaged wires, or thin wires are some of the other reasons why jumper cables get overheated quickly. To avoid such issues next time, go through this guide to find out some possible reasons you need to look out for to prevent melting the cables. 

How To Jumpstart Your Vehicle’s Battery Safely?

Before you find out the reasons why your jumper cables are getting overheated, let’s find out how to jumpstart the batteries safely by following the below steps:

  • After parking, both vehicles on the roadside put the gear on neutral mode and turned the ignition switch off for both vehicles. 
  • Get the parking brakes engaged. 
  • Grab the jumper cables and inspect if it has any defects. Avoid using the cables if you notice even slight damages.
  • Attach one end of the red clip to your battery’s positive terminal and the other end of the red clip to the adjacent car’s positive terminal.
  • Next, attach one end of the black clip to the adjacent vehicle’s negative terminal and the other end of the black clip to a metallic surface that is quite far from your car’s battery. Note that the metallic surface should not be painted. 
  • Once you have followed through with the whole procedure mentioned above, make sure to double-check everything is in right place.       

Any misalignment in the terminal connection or loose or damaged wires can cause the cables to get heated up and smoke. 

Why Do Jumper Cables Get Overheated?

Jumper cables tend to get heated up and release smoke even if you make the slightest mistakes as electricity flows through the cables, and any wrong connection or damage can cause the cables to heat up. Here are some common reasons that overheat and meltdown the cables. 

1. Wrong or reversed cable connection

One of the major reasons for overheated and smoking jumper cables is caused due to reversing the connections to the wrong terminal. The reversed cables cause electricity to flow through the wires releasing excessive heat, which eventually melts down the insulation of the jumper cables. 

Before you try starting the engine, make sure that the jumper cables are connected to the appropriate terminals of the batteries. Ensure that the red jumper cables clamps are connected to the positive ends, and the black cable clamps are attached to the negative posts of both cars. 

If the cable connections are crossed or reversed to the wrong terminals, it will result in inverted polarity. In other words, the current starts flowing in the opposite direction, causing an electrical failure.

Due to the reversed current, the cable starts getting heated up, and the rubber and plastic installations tend to meltdown, releasing smoke. If you’re in for some bad luck, in some cases, it may even completely damage your car.

2. Using low-quality jumper cables

It is a simple and easy task to kickstart your flat battery by connecting it to a good one using jumper cables. However, if you use substandard cables or the wrong type of wires to connect, it can cause serious issues. The reason is, that cable wires are made using metallic components. 

Each metallic wire reacts differently when electricity passes through them. For this reason, copper is commonly used in most electrical systems to conduct electricity as it does not get heated up quickly. As copper is quite costly, most manufacturers opt for aluminum wires to reduce the production cost.

While purchasing jumper cables, make sure to make a decent investment and get good quality wires. If you opt for cheaper cables, they will not be able to conduct electricity properly to start your vehicle.

Aluminum jumper cables require more electricity to transfer power from one battery to the other terminal. As more electricity passes through the wires, the cables get hot and start to smoke.

3. Damaged cables

To avoid your jumper cables from getting damaged, you need to ensure that they are stored in good condition when not in use. When copper cables are exposed to poor conditions, the wires will not be able to transport electricity properly. 

Storing cables in high temperatures will result in physical damage such as cracking or splitting of the wires. This will harm the flow of current through the cables. Besides, exposing the cables to high heat can melt the protective insulation layer. Using these wires to jumpstart the battery can be quite dangerous as it may completely melt down the connection and even damage your vehicle. 

Also, keep these cables away from moisture and store them in a cool and dry place. When the copper lines come in contact with water, the ability to conduct electricity diminishes.  

How to Prevent the Cables from Melting?

When your vehicle lacks power due to a flat battery, jumper cables help charge the battery and get your vehicle back on the road. Unfortunately, not all drivers are aware of how to use the jumpstart cables correctly. Connecting the jumper cables to the wrong battery terminals will result in overheating cables and the plastic insulators melting down. 

Though the latest models have safety measures to prevent the batteries from exploding, it’s advisable to practice precautions at all times. The best way to avoid this mistake is to depend on the color codes and prescribe necessary precautions to avoid cable melting.

Match the cables to the positive and negative terminals by looking out for the Plus and Minus symbols. Lastly, double-check the entire connection once again before starting the car.  

Liam Dare

As CEO of, my passion for the automotive world motivates me to build online businesses that provide information and entertainment to users. I am proud to contribute in a positive way to the automotive community.