Do you hook up the positive or negative first

Never connect the black cable to the negative (–) terminal on your dead battery. This is very dangerous, could result in a possible explosion. Make sure you follow the instructions in your owner's manual when jumpstarting your vehicle.

When connecting a car's battery cables to the terminals, ensure to put the positive first before the negative cable. This is because the positive cable will not arc if your wrench or spanner touches the car's body in the process of tightening up the cable due to the absence of the ground (negative cable).

Attach the red jumper cables first. Start by clamping one red cable to the positive side of the battery that won't start. Then attach the other red clamp to the positive side of the working battery. Next, clamp one black cable to the negative side of the working battery.