Should the Positive or Negative Terminal Be Disconnected When Cutting Off Power to a Car?
1 Answers
When cutting off power to a car, it is necessary to disconnect the negative terminal, not the positive one, and there is no need to disconnect both terminals. This is because as long as one end is disconnected, the circuit cannot form a loop, and no further power will be consumed. If you want to disconnect both the positive and negative terminals, or replace the battery, you should also disconnect the negative terminal first, followed by the positive terminal. During installation, connect the positive terminal first, then the negative terminal. The specific reasons are as follows: 1. Reason for disconnecting the negative terminal first: The car's negative terminal is connected to the body, which is made of metal. The entire car body serves as the negative terminal, meaning the body itself functions as the negative terminal. This way, the negative terminal of any electrical component only needs to be connected to the body (ground), and the current will return to the negative terminal through the body. This eliminates the need to run a separate wire from each component to the negative terminal, significantly reducing the amount of wiring and simplifying circuit troubleshooting. 2. Consequences of disconnecting the positive terminal first: If the positive terminal of the battery is disconnected, since the wrench is made of metal and conducts electricity, accidentally touching a metal part of the car body during the disconnection process would be equivalent to directly connecting the battery's positive terminal to the negative terminal, causing a short circuit.
