well, I've tried but the only way to get to the subs is to remove the lower dash and take out the center console. I think I've found a list of wire colors for the subs, but they don't seem to match the wiring diagram I have.

quoted from another forum referring to a 2004 bose system:

thanks for the input guys. I figured out the problem. If you have a chevy pickup with the BOSE system You have to find and use the speaker wire going to the two subs under the console. I did this & I'm getting exactly what I wanted and expected. It took a lot of iternet research and phone calls to a few shops to figure this out, so I will outline the process incase anyone else has this issue.
-----------------------

installing an amp and sub into a chevy silverado ext cab with the BOSE system:

first thing first: you already have two subs (6") and an amp in the truck; they are located under the center console. Unscrew all the screws holding the storage box in place and pull it out, then pull out the cup holder. You should see the factory amp under the storage box. The two subs are too hard to get to so don't worry about finding them, but incase you are wondering they are towards the front of the truck almost directly below the a/c controls. Before you take all this apart you should go buy a decent line output converter (LOC). I used the slc-4 ( http://www.scosche.com/products/sfID...productID/1388 ). hindsight being 20/20 I think something like the scosche LOC-80 ( http://www.scosche.com/products/sfID...productID/1387 ) would of worked just fine if not better. you can get either at Wal-Mart for under 20 bucks. I hooked up the slc-4 by connecting the 4 wires going to the two factory subs as left rear & right rear on the box and switched the LOC to line-in.

The wires for the subs are found on the passenger side of the factory amp. they are:

left sub is
Lt Grn\Blk(-)
DkBlu\Wht(+)

Right sub is
Dk Grn (+)
Lt Blu\Blk(-)


splice into all four wires and connect to the LOC following the manufacture instructions. Run your RCA cables to your new amp and you should be good to go. The rest is a typical install from here on out. It took two days worth of looking through forums and doing Google searches to figure this out... hopefully I have given enough details that it wont take you that much wasted time to get the job done.

The key here is that you have to get your amp inputs from the factory sub wiring.. which is found on the passenger side of the factory amp.


2004 chevorlet silverado extended cab bose factory system.

hope this saves someone some time and trouble along the way.
Now compare those colors to the ones on my diagram I showed in previous post. Unless I'm just retarded they don't match anything.