Should you disconnect the positive or negative terminal?

The negative () cable is the ground cable; it is always connected to the frame or body metal and can safely be disconnected first with no chance of causing sparks. By the same token, always reconnect the positive cable before connecting the negative cable.

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

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.

Do I need to disconnect positive terminal?

The grounded terminal should be disconnected first to ensure that a battery dead-short does not occur, should the spanner disconnecting the other one contact a nearby grounded metal part. A battery dead-short will result in short circuit currents of the order of hundreds of amperes and heavy sparks.

Is it OK to just disconnect the negative terminal?

Disconnect battery negative cable

It is a good practice to always disconnect your negative battery terminal first, to minimize the risk of sparks that can lead to car electronics damage and battery explosion. Once you have located the negative terminal, use the wrench to free the nut that tightens the terminal.

Which battery terminal to disconnect first, connect first?

Do I disconnect the positive or negative to check the alternator?

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.

Which battery cable do you disconnect for storage?

If you plan on storing a vehicle for an extended period, it's advisable to disconnect at least the negative terminal from your car battery. This prevents unnecessary battery drain, as a fully charged battery can hold its charge for 6-12 months if you do this.

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 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.

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.

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.

What terminal do you remove first on a battery?

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.

What happens if you disconnect the positive terminal while car is running?

If your alternator is malfunctioning by over-charging your battery, disconnecting it may allow the alternator to provide an even higher voltage to the car electronics, and potentially damage those sensitive components.

How do I keep my car battery from dying when not in use in winter?

Should I disconnect battery if car parked long term?

If you don't have access to an outlet - say, in a long-term airport parking lot - your second option is to disconnect the battery. That'll preserve the battery's charge, so when you reconnect it, the truck should start right up.

How do you keep a car battery from dying when not in use?

Which battery cable do you remove to test your alternator?

How do you start a car with a bad alternator?

Can a car stay running without a battery?

A modern vehicle will NOT run with a dead alternator and a low battery. If the alternator is working properly it will stay running without the battery.

Does disconnecting the battery clear codes?

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

Do you have to reset car computer after replacing battery?

Most ECUs are self-learning and should reset themselves after learning that a new battery has been installed. If you're stuck, go to a mechanic for diagnostic assistance.

How do I reprogram my car after changing the battery?

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

The readiness monitors will remain until the car has been driven long enough for the computer to evaluate the various system and sensors. The amount of time can vary based on the vehicle. In some cases it can take up to 100 miles for all of the computer monitors to completely reset.