# Question: Which Battery Cable Goes On First Positive Or Negative?

## What happens if positive and negative wires touch?

Why do the positive and negative wires spark when touched.

Since these wires have a difference in electrical potential (voltage) current will flow and you’ll get a spark.

It’s a process: The physical contact between the wires gets broken..

## Why do you connect the negative cable to the engine block?

Since the entire engine block is grounded to the negative terminal, the cable need not be connected directly to the dead battery’s negative terminal, and in fact it would be unwise to do so as sparks from the connection (when the circuit is completed) could ignite the battery.

## Do you cut positive or negative first?

Cut the 12-volt battery cables. Cut the black (negative) first and then the red (positive). Be sure that the cables are double cut so the memory in the cable does not bring them back into contact.

## Which battery terminal must be disconnected first and why?

Always work on the negative terminal before the positive when you disconnect your battery. Grab a socket from your socket kit and hold it near, but not against, the nut on the negative terminal of your battery. Ascertain visually the socket size you’ll need to loosen the nut.

## Do I have to disconnect both battery terminals?

You can disconnect whichever terminal you want, or even both, it won’t discharge. Whichever one you choose results in an open circuit so no current can possibly flow.

## Which wire do you cut first?

First cut the 2 hot wires one at a time, while leaving the neutral for last. Make sure to remember that your cutting tool will become energized as you make the cut, so make sure it isn’t touching anything but the wire being cut.

## How do I know which battery cable is positive?

Put one test lead on each terminal. If your meter is reading positive, then your red wire is on Positive. If it is reading negative then the red wire is on Negative. Typically, the cable that is put on the positive terminal is longer.

## Which side of the battery is positive and negative?

Each battery has two metal terminals. One is marked positive (+), the other negative (-). There are also positive and negative cables in the jumper cable set. The red one is positive (+), the black one is negative (-).

## Why do you remove negative battery cable first?

Expert Reply: By removing the negative battery cable you are disconnecting the battery from the chassis of your vehicle. If you begin to remove the positive side before the negative and your wrench would make contact with any part of the vehicle, then you could cause a short in the system.

## Where do you connect the negative wire?

The positive (red) cable should be attached to the positive terminals on each battery. The negative (black) cable should have one end attached to the negative terminal of the dead battery, and one end grounded.

## Do you connect the positive or negative first on a car battery?

“Positive first, then negative. When disconnecting the cables from the old battery, disconnect the negative first, then the positive.

## What happens if you connect the negative terminal first?

It is only a safety issue. If you first connect the negative cable, then when you connect the positive cable there is a chance the wrench will complete a circuit between the battery and the chassis of the car. … If the battery is offgassing, the spark could ignite those gases causing an explosion.

## What happens if you connect positive to negative on a battery?

What happens if you accidentally interchange the positive and the negative clamps? A rapid spike in the electrical power from the donor battery will damage the dead battery and the vehicle’s electrical systems. … In extreme cases, the battery can crack, ignite, then explode.

## What happens if battery polarity is reversed?

Reverse Polarity – this is when the positive and negative polarity on the battery is reversed. When connecting a reverse polarity battery to a device, the plug that is factory installed with wires reversed on it by the battery manufacturer will keep you from hooking it up incorrectly.

## What happens if you charge a battery the wrong way?

For all intents and purposes, the battery will be ruined. You could technically charge it up, negatively, and continue to use it, but your plates are designed with the positive plates being lead dioxide, and the negative being composed of a sponge lead, which would now be reversed.