I know that radios are expensive and that we all want to save a few bucks. But passing on the adapter harness and trying to wire in the radio directly to the body wiring is quite possibly one of the biggest mistakes you can make.
A) You will lose your door chimes. Which if they are disabled, it can make it difficult to resell the vehicle or trade it in.
B) You will lose your OnStar functionality (if installed)
C) Chevy doesn't have any particular method to their madness when labelling what wire is what and more often than not, doesn't make any sense to the nomenclature used in the aftermarket schematics (which actually follow a standard!).
D) IT'S $100!!! SERIOUSLY!!
E) Installing the aftermarket harness is easier and faster.
So you may ask, "Oh great and powerful Will! How do I know what harness to get as I don't possess the infinite knowledge in your noggin!)
Here's how: Crutchfield: LCD TV, Car Stereo, Home Theater, Speakers, Digital Cameras
Go there and you'll see a menu called Car Audio/Video&GPS, and then Outfit my car.
Then it will ask you for the Year, Make, Model, Body Style (if applicable), and last but most certainly not least, what original equipment you have or had installed on the car.
It may also ask if you already have a factory or aftermarket stereo installed as well.
Then you can click on Car Receivers, In dash DVD Receivers or In dash GPS Navigation depending on what you have or want to install.
Once you find your radio, it'll tell you everything you need to know. Including WHETHER IT FITS OR NOT!!!
And if you click on Installation Info...oh HAI!
You know what harness to install, how much it costs, and where to get it from.
To see how easy it is with the adapter harness...
Everything is color coded to the standard colors that the aftermarket manufacturers adhere to. With solder splicing instead of butt splicing it took me half an hour to build the harness to get it into the car. And all I had to do was plug it in.
So before you cut into your factory harness, please do the above. Because I've seen it take upwards of TWO WEEKS to get everything working correctly otherwise. It's not worth the money to skip it.