2008 chevrolet kodiak c4500 wire harness?

Need some help here.  I have a 2008 Chevrolet Kodiak C4500.  It came with the factory AM/FM CD player.  I also have the chimes that play through the front left speaker.  I do NOT have power to stereo after the key is turned off.  So, opening the door does NOT shut the stereo off.  Also, since I have removed the factory stereo and turned the ignition on, my ENGINE CHECK light stays on.

The METRA 99-2003 is the correct install kit for dash mounting.

Which wire harness am I supposed to use?  I have been sold the XSVI-2003 (does not work).

Who has actually worked on this type of new truck?  I'd really like to hear from someone who has done this. 

Thanks for your help!!!

JL

Also...

What is the wire color for the reverse lighting circuit? and if anybody knows, is there an easy spot up front to locate this wire?  Thanks.  That is for the back up camera circuit.

JL