Positive should always be connected first. The pull of electrons toward the positive terminal will cause a spark.
If all you did was disconnect and reconnect the battery, it should function as normal. That is, assuming you disconnected the ground (negative) first when you took the battery out and reconnected the positive side first when replacing the battery. If you didn't, there's a possibility you toasted your ECM.
When servicing a battery, the negative cable should be disconnected first and reconnected last. This practice helps prevent sparks and reduces the risk of a short circuit if the tool touches any metal while working on the positive terminal. Always ensure safety by wearing appropriate gear and following manufacturer instructions.
When charging a battery, you should always connect the red cable first before the black cable.
the first cable - after +
When connecting a battery to a vehicle, the red positive cable should be connected first.
If your car is completely dead after disconnecting and reconnecting the battery cable, it could be due to a few reasons. First, the battery might have been weak or drained before disconnecting, and reconnecting it didn’t provide enough power to start the car. Second, there could be an issue with the battery terminals, such as corrosion or loose connections, preventing proper contact. Lastly, if the battery was reconnected incorrectly, it may have caused a short circuit or damaged the electrical system.
The negative battery cable from the battery.
Connect the negative cable first.
When charging a battery, it is recommended to connect the red cable first, followed by the black cable. This is the standard procedure to ensure safe and proper charging.
When jumping a car battery, the red positive cable should be connected first.
When charging a car battery, the red positive cable should be connected first.
Disconnect the negative cable first when disconnecting a car battery