Reason being, electrons don’t know the color of their wire.
Sparking can result in explosions, so it is wise to connect the ground end of a jumper cable instead. Do not connect directly to a dead battery when connecting negative ends together; find another method instead.
Connecting the Negative
When jumping a car, it is critical that the negative cable leads are connected correctly in order to protect both battery and vehicle components from possible damage during a jump. Failure to do this may cause sparks to fly during the process and possibly result in explosion or fire hazards.
Locate both batteries’ positive and negative terminals – usually marked with “+” signs or red plastic caps – before connecting cables. Be absolutely certain of which terminal represents positive power before you begin making connections.
Attach one end of a red jumper cable clamp to the positive terminal of a dead battery, and connect its other end to that of a good battery. Make sure the clamp “bites” onto each battery terminal securely – if corrosion forms at any point on either terminal, simply twist its jaws to break through it!
Once this connection is made, move onto the other car to establish additional connections. When connecting the other end of your red cable clamp to any of the dead or working cars (such as engine blocks ), be careful that it doesn’t touch any metallic surfaces such as engine blocks.
Alternatively, when using a portable jump starter, simply connect its negative lead directly to ground in order to lower the risk of sparks that could damage both your car’s electrical system and alternator. Doing this will minimize sparks that could endanger the safety of both systems.
Connecting the negative cable to a grounded surface also serves an additional purpose: it prevents electrical arcs from forming near either dead or working batteries, which could spark explosions of explosive gases and ignite fires if left unchecked. This is particularly dangerous for older vehicles that feature fuel lines close to their battery, or those without many grounding points nearby.
Be careful to connect the negative lead of your car’s chassis or engine block using non-moving metal parts, such as an accessory bracket or bolt. This will keep cables away from moving components such as belts and fans.
Connecting the Positive
Jumper cables should always be connected to the positive terminal of a dead battery’s positive terminal (usually marked by + or POS signs) first and foremost when used to jump start it. Once this step has been accomplished, attaching red cable will do just fine to jump start your vehicle’s engine!
After connecting the black (negative) end of your jumper cable, connect its black (negative) end to a metal surface on either car that is free of fuel lines or other sensitive components, in order to decrease any chances of hydrogen gas igniting upon spark near the battery, which could potentially result in an explosion and cause physical injury.
Counterintuitively, but this step is vitally important! Lead acid batteries produce highly flammable hydrogen gas when charged, which can easily be ignited by sparks. Therefore, never connect your negative jumper cable directly to the negative battery terminal.
Jumper cables typically contain two connector clamps at either end: red for positive and black for negative connections. Each side should use their respective color. The red clamp should connect positively, while black is used as the negative terminal.
To connect the positive, use one of the red clamps to connect with the battery terminal of a car with dead batteries, while connecting another red clamp with functioning car’s positive terminal. After both clamps have been connected securely, disconnect them in reverse order in order to avoid shorting or damage occurring between both vehicles.
Now is an opportune moment to restart the engine of a previously disabled vehicle and allow it to run for several minutes in order to charge its battery, and also check for any damage you might have caused while jumping the vehicle.
This test can help determine if it is necessary to take your car to a mechanic, or simply clean its battery terminals before trying to start it yourself. If any concerns arise, seek the advice of an expert before trying anything yourself.
Connecting the Clamps
Reason #1 for not connecting the negative is simple – connecting could ignite hydrogen gas that seeps from batteries and spark an explosion. To decrease risk and lower chances, move the final black/negative jumper cable clamp away from battery terminal.
Attaching red and black cable clamps requires following a strict rule: start by attaching the positive (red) clamp, followed by attaching negative (black). This ensures only energy is being fed into one car while also limiting any risk of sparks that could ignite gases.
If you are unfamiliar with how to identify the positive and negative terminals on each battery, look for either a stamped-in “+” or “-” symbol, or a red plastic cap with an inverted “minus sign.” This will help identify which side is positive so that when connecting jumper cables you know where each end should go.
Once the red and black cables have been attached, move onto the second battery (with a working/good one) to make connections for it. Clamp the red (positive) jumper cable end onto the positive terminal on the dead battery; and clamp its matching black (negative) end around a clean metal part of your engine in the car with weak battery.
Before making connections, be careful to avoid touching any other parts of the engine – including its carburetor/fuel-injection system – during this process. Doing this will reduce any chances of sparking, which could ignite gasses that could explode the battery or trigger an explosion.
Be wary when connecting red and black jumper cables if you are trying to jump-start a dead battery; do it carefully when making connections. If the engine won’t crank, contact professional roadside assistance instead of trying to do it yourself.
Once this has been accomplished, disengage both positive and negative cables in reverse order, starting by unclamping their connection from the car with a good battery before unclamping their connection from another car with poor batteries, then unclamping both cables from both cars, then unclamping both at once from “ground”, usually an unpainted metal piece in your engine bay or frame/chassis (but you could also try removing an accessory bracket or large bolt provided it’s free from paint and doesn’t overlap the battery area).
Connecting the Cables
Jump starting a car is never recommended due to hydrogen gas produced when charging or discharging, which a spark could ignite and result in blowing apart or spraying acid over everything nearby.
To reduce the chances of this happening, connect the negative lead to a metal part on the car being jumped away from its battery. This will decrease the chances of sparking and allow hydrogen gas to burn off without creating sparks close by where hydrogen may ignite.
Once the cables have been connected properly, the next step is to connect the jumper clamps. Each end of a jumper cable comes equipped with two connector clamps – red for positive, and black for negative connections.
Attach the first red cable clamp to the positive terminal of a dead car’s battery and use another red clamp on its working (live) battery’s positive terminal. Use either red clamp if your terminals have different colors or have plastic covers as long as both connections are securely fastened together.
Portable jump starter users should connect their other negative cable clamp to an engine block or similar piece of metal on the car being jumped, in order to ground their negative lead and prevent hydrogen gas from being ignited during disconnection.
Once all clamps have been connected, power up both cars’ batteries and let them idle for a few minutes before trying to start up your dead car and see if it starts – if not, disconnect and retry!
Safety glasses should always be worn when connecting or disconnecting jumper cables. Doing this helps protect the eyes from electric arcs and reduce the chance of explosion or injury. Furthermore, it is wise to go slowly and carefully when handling jumper cables.