Car Stereos: Bose stereo without onstar, chevrolet silverado, stock speakers

Question
Hi I Own a 2003 chevrolet silverado with the stock bose audio system in it but it does not have onstar and i am looking to put a deck in it keep the speakers and buy an aftermarket amp and two subs so i was wondering what wiring harness i need to but in it and how to wire the subs and amp

Answer
Hi Tyler,

If you're keeping the stock speakers in your truck, you'll need to keep the stock Bose amplifier working as well.  The correct adapter to integrate an after-market head unit with the factory amplifier is Metra's GMOS-04.  (This adapter is designed to retain the Onstar function, but it will work in a non-Onstar vehicle as well).  

For best results, you'll need to choose an after-market head unit that has separate RCA pre-amp outputs for front, rear, and subwoofer channels.  The GMOS-04 uses the low-level RCA pre-outs, instead of the speaker outputs, from the new head unit.  Choosing a model with three sets of outputs will let you use the front and rear outputs with the GMOS-04, with a dedicated subwoofer output that can be connected to your after-market amplifier.

Hope this helps!

Brian