I had some extra wire over from an amp install so I am going to make some new ground wires to my engine. So here is the question. Before swapping the wires for the OEM ones, do I need to take the batter terminals off or doesn't it matter if the car is off?

Thanks

 

Don't matter. Just don't touch anything to the starter wire or the alternator wire...

 

Thanks man... I am just replacing the tranny wire, block wire, and head wire.