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.

Will unplugging battery reset car?

Does Disconnecting Battery Reset Check Engine Light? Yes, disconnecting the engine is one method of resetting your check engine light. ... Other experts recommend turning on the light switch for a few minutes (the lights won't come on) after disconnecting the engine to drain any remaining current on the computer.

What happens if you disconnect the positive terminal first?

It can fall across either terminal and the car and nothing will happen. If you disconnect the positive terminal first and you drop a spanner, it is possible for it to fall across the positive terminal and any earth on the car, with spectacular and possible dangerous results.