when jumping a car what cables go first

[StCatherine]

When jump-starting a car, you should always connect the positive (red) cable to the dead battery's positive terminal first. The correct, safe order is: Red to Dead, Red to Booster, Black to Booster, Black to Metal. The final connection is the crucial safety step—instead of connecting the black clamp to the dead battery's negative terminal, you attach it to an unpainted metal surface on the dead car's engine block or chassis. This is a ground connection that minimizes the risk of a spark igniting hydrogen gas potentially emitted from the battery.

The logic behind this sequence is all about managing risk. Car batteries can produce flammable hydrogen gas. By connecting the positive cables first and completing the circuit with a ground away from the battery itself, you ensure any small spark occurs at a safe distance from the potential source of gas. This standard procedure is endorsed by the American Automobile Association (AAA) and most vehicle manufacturers.

Here’s a quick reference table for the correct connection steps:

Step	Cable Color	Connection Point	Rationale
1	Red (+)	Dead Battery's Positive Terminal	Establishes the primary power path.
2	Red (+)	Booster Battery's Positive Terminal	Completes the positive circuit.
3	Black (-)	Booster Battery's Negative Terminal	Establishes the ground path from the good battery.
4	Black (-)	Unpainted Metal on Dead Car's Engine	Finalizes the circuit safely, away from battery gases.

After the car with the dead battery starts, carefully remove the cables in the reverse order: black from the ground on the dead car, black from the booster car, red from the booster car, and finally, red from the formerly dead car. Let the jumped car run for at least 15-20 minutes to allow the alternator to recharge the battery.

[VanKylie]

Red on dead first, always. Hook up the red clip to the positive terminal on the dead battery. Then, the other red to the good battery. Next, black to the good battery's negative. For the last clip, don't put it on the dead battery. Find a shiny metal bolt on the engine—that's your spot for the final black clamp. This keeps any spark away from the battery. Reverse the order to disconnect once it's running. It's a simple safety habit that takes two seconds but prevents a nasty surprise.

[VonPhoebe]

The most important thing to remember is the final connection. You connect the positive (red) cables to both batteries first. Then, you connect the black cable to the good battery. For the last black clamp, you must attach it to a bare metal part of the engine block or chassis of the car with the dead battery, not to the battery's negative post itself. This creates a safer ground and is the step that truly prevents a dangerous spark near the battery, which is the whole point of the specific order.

[ElleDella]

I learned this the hard way after helping a neighbor. You start with the red cable on the dead car’s positive terminal—it has a plus sign. Then the other red on the working car. The black goes on the working car’s negative terminal. The last step is what matters: find an unpainted metal bracket or bolt on the dead car’s engine, far from the battery, for that final black clamp. It feels counterintuitive not to complete the circuit at the battery, but that’s exactly what makes it safe. It ensures if there’s a spark, it’s nowhere near the battery.

[Gutierrez]

Think of it as managing risk. The correct sequence is positive to dead, positive to booster, negative to booster, and then negative to a metal ground on the dead car. This procedure is designed to keep the final connection—and any potential spark—as far from the battery as possible. Modern batteries are sealed but can still vent gas under certain conditions. By grounding the circuit to the chassis instead of the battery terminal, you effectively use the car's entire frame as a conductor, which is safer and just as effective for completing the jump-start.