once a battery is connected even if the key is not in the ignition, there is always power at certain points in your car. Connecting a battery backwards will not start your car, but it can and will fry the wires to your starter.
it will arch out and melt the knobs on your battery and your cables
Depending on the age of the vehicle you probably have shorted or grounded the electrical system causing fuse(s) to blow. Question was kind of broad may want to be more specific
Nothing as long as you did not then connect the other cable.
If you connect a negative battery terminal to another negative terminal, you would be creating a short circuit, which can lead to excessive current flow and potential damage to the battery or the connected devices. It is not a recommended practice and can be dangerous.
When you connect the battery backwards you can cause major damage. You can blow the alternator or its fusible link. You can destroy electronics, particularly the various computers - and these are not cheap.
Very Dangerous........it would be a dead short. andcouldcause a fire or explosion.
You cannot charge it connected backwards. You will destroy the battery.
Voltmeter will give you opposite readings or will not work at all.
Dead battery -will no longer charge.
When you connect jump leads backwards, meaning the positive (red) lead is attached to the negative (black) terminal and vice versa, it can cause a short circuit. This can damage the battery, the vehicle's electrical system, or even lead to sparks and potential battery explosion. Additionally, it may blow fuses or damage sensitive electronic components in the car. It's crucial to always double-check connections to prevent these hazards.
What happens when you inadvertently crossed the positive battery terminal from a negative to a positive and a positive to a negative.?Read more: What_happens_when_you_inadvertanly_crossed_the_positive_battery_terminal_from_a_negative_to_a_positive_and_a_positive_to_a_negative.
When replacing the battery on my son's Kawasaki Vulcan 500, I accidentally hooked up the battery backwards. I had purchased an EverStart battery from Wal-Mart and the orientation of the main battery terminals was backwards from the original battery. Anyway, it blew the main fuse located in the left hand side side cover.