My post is based on 9 volt connector being wired correctly to begin with, if color wires are reversed in error you will get voltage spark so when you plug in first time don't shove it in, plug in slowly to see if it sparks, you will know.
Easy is, battery female ikelite facing you.. put the alignment hole on top.. the left pin is pos..
on the stock battery cable the brown wire is the Hot/pos.