Attach the red jumper cables first. Start by clamping one red cable to the positive side of the battery that wont 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.

What order do I connect battery cables?

“Positive first, then negative. When disconnecting the cables from the old battery, disconnect the negative first, then the positive. Connect the new battery in the reverse order, positive then negative.”

What order do you put on and take off jumper cables?

Turn off the cables in reverse order First remove the negative cable from the car that is jumped, then the negative cable from the car with the right battery. Then remove the positive cable from the car with the right battery (do not touch a part on the floor of one of the cars with the positive cable clamp).

Which jump lead comes off first?

Turn off and disconnect Turn off the engine. Remove the leads in the reverse order to how you placed them on (first disconnect the black lead, then the red lead).

What happens if you put the positive cable on the negative battery post?

Connecting the positive terminal of each battery to the negative terminal of the other battery will result in a huge surge of electrical current between the two batteries. The heat can melt internal and external battery parts, while the pressure from the hydrogen gas can crack the battery casing.

What happens when you connect the wrong jumper cables?

When the jumper cables are incorrectly connected, the polarity of the electrical system on the vehicle with the dead battery will be reversed for a few seconds. This can irreparably damage many of the sensitive electronic components that are common on todays vehicles, such as on-board computers and electronic sensors.