2003 Yukon Wiring Diagram Needed

I have a 2003 Yukon and am trying to hook up custom speakers...i have the module that converts to RCA jacks for the amp but I cant find the right/left +/- audio wires to hook to the module's wires.  I know the colors for a 97 Tahoe.  There are wires that are identical to those in the 97 Tahoe except they are after the factory amp and do not send current through my amp to my custom speakers.  Also connecting into the factory amp is another wire harness with 7 wires of various colors which come from the 6-disc in dash CD player.  I think these are the wires I need to hook up to but I do not know which ones...if you could please help it would be much appreciated.  I do have onstar and the 9 speaker Bose system.

I have a 2003 Tahoe and ran into the same problem.   First of all if you can afford to, get rid of the factory deck and use a relocation harness in order to keep factory settings and functions the radio stores and uses.  Factory decks and hi/low level converters like what you are using are known for poor sound quality and engine noise.  If you must know where the wires are, they are in the side of the dash on both drivers and passengers side of the vehicle under the access panels.  Bose systems are generally something you dont touch unless you totally bypass it.  Hope you take my suggestion and get a new deck and relocation harness.  Another thing to remember is you need to tag the wires after the amp because on the deck side of the amp you wont be doing any good.  If you test the wires on the back of the deck they will show 6 volts if im not mistaken.  IF you have to you can always pull the door panels and look at the colors coming off the factory speakers.  MAke sure you get left and rights though, so u maintain good imaging. 

so technically i could go into the pillars in the rear and tap into the wires going to the rear speakers there which are of the colors that match the wires in my 97 tahoe???  connect them to my converter and then inot my amp and it should work correct???