What happens if I 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.

Can I remove positive battery terminal first?

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.” When you are replacing your car battery, It isn't always easy to remember the order in which to disconnect and reconnect the terminals.

What happens if you remove the positive cable 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.

What happens if you only disconnect the positive terminal?

when the positive terminal is disconnected, it will arc when it comes into contact with just about any unpainted metal part of the car. The terminal doesn't have to touch a metal part directly, it can (and will) go through metal tools (like a spanner, screwdriver or pliers).

What happens if you disconnect the positive battery?

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.

Which battery terminal to disconnect first, connect first?

Do I need to disconnect both battery terminals to work on car?

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.

Will disconnecting car battery harm computer?

Disconnecting or replacing a battery on a computer-equipped vehicle may cause starting, driveability and a number of other problems, including loss of air conditioning, power accessory functions (door windows, seats, sunroof), false warning lights, even damage to certain electronic modules!

Do you take the positive or negative off to test the alternator?

If you're tempted to test an alternator by disconnecting the negative battery cable, don't do it. A good alternator may indeed keep the engine running without the negative cable, but this was never a good test. In the pre-computer days, you could pull it off without damaging anything.

What happens if you disconnect positive before negative?

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.

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 the positive terminal touches metal?

So when a “piece of metal” touched the positive post—-that piece had to be connected to ground. You thus functionally “shorted out” the battery, if not corrected, this will damage the battery and could cause a fire.

Which battery cable do you disconnect to see if alternator is bad?

You can check the alternator by simply starting your car and then disconnecting the negative battery cable. Be careful doing this, though, because there are a lot of moving parts in your engine compartment that could cause injury.

Can you remove battery from running car?

It is a good idea to never disconnect the battery while the engine is running or the ignition key is on, regardless of the year. It can cause a high voltage spike in the electrical system, which can damage electronic modules and/or the charging system if done.

Does disconnecting car battery clear codes?

Disconnecting the battery will clear the error codes and reset the check engine light.

How long does it take for a car computer to reset?

Here's something you probably don't know: after clearing the car's computer you will need to drive for about 50 to 100 miles. As you drive your car the computer will monitor all the sensors and register the results. You can use GOFAR to constantly monitor your car diagnostics.

Does it matter which battery terminal I disconnect 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.

Which battery terminal Do I disconnect for storage?

Which battery terminal should be disconnected for storage? It is always recommended to disconnect the negative terminal first. When connecting the battery, however, the order will be opposite: Positive end first, then negative terminal after.

Should a battery spark when disconnecting?

Yes, a battery will spark when it's being connected. Electronics in your car like your lights, radio, and dash clock are looking for some juice.

Can I disconnect positive terminal while car is running?

Does Disconnecting Battery Hurt Your Car? It is a good idea to never disconnect the battery while the engine is running or the ignition key is on, regardless of the year. It can cause a high voltage spike in the electrical system, which can damage electronic modules and/or the charging system if done.

Will engine run with battery disconnected?

If the engine's already running, disconnecting the battery will still keep the engine running. If you're trying to start a car without a battery or with a very dead battery, it won't start (even with push start in a manual car) because there's no electrical supply (spark) to the combustion chamber.

Why should you never unplug anything while the engine is running?

Here's why... Your battery does more than just provide electricity. It also shorts AC, spikes and transients to ground. Removing the battery from the circuit allows those spikes and transients to travel around, endangering every semiconductor circuit in your car.