Is it OK to just disconnect the positive terminal?

Disconnecting either cable works. The reason they say to disconnect the negative and not the positive is because while taking the positive connection off with a wrench if you happen to touch anything with the wrench while it's on the positive terminal it can arc and be dangerous.

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.

Can you disconnect battery from positive terminal?

The terminals will be marked positive and negative. 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.

Can I disconnect the positive terminal first?

“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.”

Can you just disconnect the positive terminal?

Should battery Disconnect be on positive or negative?

The negative cable connects to the body ground already—so there's no additional danger if it rubs. It's the same principle as why you should always disconnect the battery's negative side first before performing electrical service.

Is it safe to disconnect car battery?

You should never attempt to disconnect your car's battery while your car is powered on. We'd also recommend using safety equipment, like gloves and safety goggles, if you have them on hand.

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.

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.

How long will a car battery last if disconnected?

If you know you won't be using your car for a while or won't be able to recharge it weekly, it may be best to disconnect it completely from the vehicle. When stored properly out of the car in a secure place, a detached car battery has the chance to last up to six months.

Will I need a radio code if I disconnect my car battery?

Changing your car battery

However unless you put some thought into preparing for changing the battery you can find yourself unable to use your radio. This is because some vehicle manufacturers - as an anti-theft measure - disable the radio if the power is cut until a special security code is entered.

Do I need to reset car after changing battery?

Yes. You will need to reset your settings. Usually the dealer can do it free of charge but no promises. If you take a battery off and put a new one on, if there was anything hooked up the the battery, i.e. the hose you are speaking of, reinstall it.

Can a battery drain with the negative cable disconnected?

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.

What happens if I disconnect negative battery terminal?

If you remove the negative clamp and inadvertently complete a circuit to ground, there will be no current flow because the ground clamp is already grounded. Subsequent shorting of the positive terminal to ground will then produce no current flow because the current has no return path to the negative post.

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.

What battery cable do I take off to check 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.

Why do you connect the positive terminal 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.

Should fuse go on positive or negative?

Recommended practice is to place the fuse near the positive terminal of the battery, so the whole circuit will be dead if the fuse blows. (Of course, if the positive terminal is considered Ground, place the fuse near the negative terminal.)

Should RV battery disconnect be on positive or negative?

Primarily when replacing or working on the battery wiring, if the negative is not disconnected you can cause a short circuit if you touch the positive lead to the RV frame. This can be avoided by disconnecting the negative first or if the battery disconnect is installed on the negative lead the risk is mitigated.

Does disconnecting the battery reset the ECU?

A. It depends on the car's age and type of ECU used. On some older cars, disconnecting the battery will reset the system but in most new cars it does nothing, except potentially reset the clock and radio station presets.

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.