The battery terminals in your car should be either marked or color-coded. If the terminals are marked, you will see a plus sign on the positive terminal and a minus sign where the negative terminal is. There's als. The negative cable should always be removed first and reconnected last. If you take the positive off first, you could create an electrical short and there is a risk of sparks, especiall. The negative battery cable should be reconnected last and the positive cable first. When you are putting a new battery in or have finished jump starting it, you have to be careful to re. If you fail to remove the negative connection from the battery first, you put yourself at risk of an electrical short. As an example, if you were to drop a metal tool on the positive termi. Although disconnecting the positive battery terminal first is possible, this is not wise, as you might damage your vehicle by doing this, or even hurt yourself. While undoing the cable lead, y.