Okay so I have a 2003 Impala 3.4L. I recently purchased a plye touch screen radio setup. I have all the wire hook ups and such. The wiring from the aftermarket is corrected labeled but how do I hook them up to my impala wires? They do not match color codes I looked that up. It says I need to connect the "parking" wire on my aftermarket to the -B on my impala in order for the screen to work, what is the color of the -B wire on my impala? I need help!