I recently got some leather seats from a junker 04 crew to put in my 06 crew. I asked GM service and parts as well as on here for some help wiring it all up, but no luck. Fortunately I stumbled on these guys: http://www.ahdol.com/
. The diagrams I got were almost 100% right, and I was able to make everything including the seat heaters work by following it [a few connector and fuse numbers were off, but the schematic was on].
For the airbag systems, I was able to carefully remove all the sensing equipment, including the seat belt buckle from the passenger seat and put it on the 04 seat in place of the simpler harness there. All the airbag systems check out and the seat senses an adult properly- we tried with a backpack and then my 2 year old sitting on the seat and it did not activate the airbag system.
I already had an LT3 trim package, the top US package, even with XM in there too, so I don't know if that makes a difference in any way or not. I rebuilt the wiring harness for the seats, which is basically 3 primary power wires split into the seating. Once comes from Power Seat fuse, and another from Heated Seat fuse and another from the 10a HVAC fuse.
So, heres a pretty cool tip for you guys that are not interested in the power seats, but need an always on source of power. While tracing the wire for the 40A Heated Seat fuse, I found it comes out in the harness on the far LH side of fusebox; It is part of the parkinglamps and headlamps loom. It is the very thick 12ga orange wire in that loom. On my truck, it ran all the way past the radiator and over to a small junction on the frame behind the air filter. Theres a small blue wire going into that connector as well. If you take apart the plug, the wire terminates there and there isnt even a connector blade to take it out the other side, where a stubby green plug is hanging out [I assume this is suppossed to house an inline 20a fuse that was shown on the drawing I had]. Anyhow, if you're looking for a hot out under the hood for something, there it is. I don't know what you could hook up with it. It is hot at all times, even with ignition off. 40A is a lot, you could put in a 30 or 20 instead.
Hope someone finds that of use.