2. I want to install a navigation system on the Rainier
I did this upgrade on both my 2004 Envoy XUV SLT (5 years ago) and on my brother's 2006 Trailblazer LT (a year ago).
Disclaimer: Below information is based on the Ranier NOT using a special Radio like the Saab.
First: The truck MUST have the Bose Option (UQA).
Second: You will need to find a Navigation Radio GM part #15800000/12597521, either the Theftlock should already be cleared (clear the VIN) or use a Tech II after install to clear VIN.
Third: You need a GPS Antenna that mounts under the dashpad forward of the radio. The correct antenna has the proper bracket attached with about a 1.5 - 2ft cable and Green Plug to plug into the Nav Radio. Other antennas may work if they have the correct green plug, but you will be on your own to mount it.
FYI: The Nav Radio (with touchscreen) listed above was originally used starting in 2006 and up vehicles but works perfect in my 2004 (non LUX) and also works in 2005 and up vehicles (all are non-LUX). You don't want the 2004/2005 version of the Nav Radio since it is NOT Touchscreen.
This is the short version, There is also a large thread on here with more part numbers and much more information.
