Why is it essential to remove the ground wire first when replacing the battery?
Before you start to replace the battery or merely clean the terminal, the first and foremost task of yours is to check out the grounding system of your car. If the ground system is negative and you try to remove the positive connector first then, it will result in a spark due to the use of a metal tool to remove the positive terminal connector that might have touched some metal part of the car. It can result in a battery explosion too. So, it is quite essential to remove the ground wire first.