I currently have my taillight off and am doing an accessory tailight deal. Obviously taillights arnt as easy as the good ol days and I dunno which wire is which! There's a black one with a greenish stripe, a grey one, and a purple one which I have found to be the turn signal. Now, which one is the ground and which one is the tailight? Its a 2011 also. Thanks!

 

black one is more than likely the ground

 

That's what I figured but I wanted to make sure