What happens if you disconnect the positive battery cable first?

If you remove the positive cable first, there is a chance your tool may come in contact with a metal surface on the vehicle and short out the battery, which can easily damage your electrical system and possibly cause the battery to explode.

Does disconnecting car battery cause problems?

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.

What happens if I unhook the battery while the car is running?

Here’s the rub: the alternator’s regulator can only react so fast to a massive step change in load, such as when you unhook the battery while the car is running. (Especially if it’s a flat battery — if you are going to unhook the battery on a running car, make sure it’s fully charged first!)

What happens when you disconnect a negative battery terminal?

The electrical power in a car’s engine is activated by the battery. Contact between the negative battery terminal and the battery, even if the cable is not clamped onto the battery, may reactivate the electrical system within the car. This would negate all the reasons you have done this much work to ensure the cable is disconnected.

How do you remove a negative battery connector?

If the cable is seized to the battery post, a special battery cable removal tool may be needed to remove the negative connector. Ask your local auto parts store or mechanic. Follow the same procedure to disconnect the positive terminal. After removing it from the terminal, don’t let the positive connector touch any metal part of the car.

What should I do if my car battery cables are disconnected?

With the battery cables disconnected, you can safely perform repairs on electrical components of the vehicle. If you just need to put in a new car battery, it can be done in a few simple steps. After the battery is disconnected, unscrew the brackets that hold it in its tray. Lift the battery straight up, out of its tray.

Can a battery drain with the negative cable disconnected?

Like I mentioned above, simply disconnecting the negative cable is not enough to stop your battery from losing charge. Don’t get me wrong, it is definitely better than nothing and it will go a long way in preserving your battery’s charge while you’re away. There’s something that every battery undergoes and that is called self-discharge.

Do you need to disconnect the positive terminal of a battery?

Gear-obsessed editors choose every product we review. We may earn money if you buy from a link. How we test gear. Follow these tips to keep your battery—and your hands—in tip-top shape. Q: A friend of mine told me that I should always disconnect the positive terminal of the battery first to keep the electricity from spilling out of the battery.