Which battery cable should be disconnected?

“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.”

Does it matter which battery cable you take off first?

Disconnect the Battery Cables

Make sure you disconnect the negative terminal first. Lay the disconnected negative cable carefully to one side, making sure it's well away from the battery terminal. Disconnect the cable from the positive battery terminal in the same way, then lay it to one side.

Should you disconnect both battery cables?

In any case, if you're working on your car's electrical system, you have to disconnect car battery negative only. There's no need to disconnect both cables.

Is it OK to just disconnect the positive terminal?

Be safe: always disconnect negative first. Disconnected either terminal will prevent drain, as stated already. A battery tender is another safe way to maintain the battery.

Should I disconnect positive or negative for storage?

In order to disconnect the battery, all you have to do is remove the cable from the negative port. Do not let the negative and positive cable ends touch under any circumstances.

Which battery terminal to disconnect first, connect first?

What happens if you remove the positive terminal first?

It's important to disconnect the negative side of the battery first, otherwise you can cause an electrical short if the positive is removed first.

Which cable should be disconnected first and reconnected last when servicing the batteries Hmmwv?

When removing a battery, always disconnect the negative cable first and be sure to use the proper tools to avoid damaging the battery posts. During installation, connect the positive cable first and the negative cable last.

When replacing the starter which cable do you disconnect first?

There are usually two wires: a positive and a negative wire. Remove the positive wire first, and then remove the negative wire from the starter.

Which battery terminal must be disconnected first and why?

Disconnect the negative terminal of the battery

You should always remove the negative battery terminal first, to reduce the risk of sparks which can make the car battery explode. Once the negative terminal has been located, use the wrench to loosen the nut that holds the terminal.

Why is negative terminal disconnected first?

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.

Do you connect black or red first when jumping a car?

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.

Which terminal of the battery should be removed first?

First, unbolt the negative battery cable and disconnect it by lifting it free. It might take some wiggling and twisting to pull it off. Be sure never to let the wrench touch both the negative and positive terminals at the same time.

Why do you connect positive first?

Connect positive first, negative having less potential won't arc. The higher the voltage, the greater the chance of arcing and fusion. On a car if negative first and you are touching any metal part of car, when attaching positive there is possibility of arcing through you. Your body becomes part of the circuit.

What happens if you disconnect the battery while the car is still running?

Removing the battery from the circuit allows those spikes and transients to travel around, endangering every semiconductor circuit in your car. The ECU, the speed sensitive steering, the memory seat adjustments, the cruise control, and even the car's stereo.

Will disconnecting car battery harm computer?

Disconnecting your car battery will not cause any permanent damage to your computer or ECU (electronic control unit), but it can have some adverse effects. Those include canceling your preset radio stations, forgetting learned shift points, and your car's ideal fuel/air mixture.

Why is my battery sparking when I hook it up?

Sparking from a battery is perfectly normal. As long as the sparks aren't massive, they don't come with smoke, and it only sparks when connections are made, there's nothing to worry about.

Do you put red on red and black on black?

Attaching the Clips:

Red to Dead - Connect the positive (red) clip to the positive terminal on the battery of the dead car. Red to Donor - Connect the positive (red) clip to the positive terminal on the donor battery on the other car. Black to Donor - Connect the black clip to the negative terminal of the donor car.

When connecting a car battery which terminal do you connect first?

Attach the positive (red) cable first, following with the negative (black) cable. Hand-tighten the nuts. Do not over tighten the terminal bolts; the following values are recommended: SAE (tapered) automotive terminal: 50 to 70 inch-lb.

Why do you connect red first?

Connecting the red terminal to the dead battery first would minimize damage if the other red clamp were accidentally dropped so as to contact the frame of that vehicle.

Does it matter what order you connect jumper cables?

Don't attach the negative (black) clamp to the negative terminal of the dead battery. It is important to connect the cables in that order, and it is safest to connect the negative (black) clamp as far from the battery as possible, in order to reduce the risk of sparking that could cause a fire or explosion.

When placing the black jumper cable on the dead car put the clamp on?

Connect one black-end clamp to the negative (-) post of the good battery. Carefully connect the other black-end clamp to some large metallic part of your car's engine block. Never connect it to the negative (-) post of the "dead" battery. This causes sparking, which could ignite battery gases.

Where do you connect the black cable on a dead car?

Clamp the negative cable (black) to the negative terminal of the good battery. Clamp the other end of the negative cable to a clean metal part of the engine (like a bolt head or bracket) in the car with the weak battery. Keep the clamp away from the battery, any moving parts and the fuel system.

Does revving the engine charge the battery?

Yes, revving the engine will still charge the battery faster.