Ok I need yalls help on what adapter I need to make this work... I have a 2003 Sierra with the Bose system and no on star. I wanna replace ...

Ok I need yalls help on what adapter I need to make this work... I have a 2003 Sierra with the Bose system and no on star. I wanna replace everything with better sounding aftermarket speakers, add a sub and change the head unit. I wouldn't mind keeping the door chimes but I really don't care and I dont wanna pay $90 for an adapter just to do so. I've been looking online and most people seem to use the adapter for the Bose system which when I keeping reading they say it let's them retain factory speakers which I dont want. So my question is do I need the expensive adapter for the Bose system or since I'm not retaining any of the old system, will the regular non Bose stuff work?...or should I just figure out the pinout on the harness and take the power & gnd etc that I need..?

Help!! I'm usually pretty good at figuring things out but I'm kinda baffled on this one..

Unless you're doing a 100% system swap, you're gonna want that adapter in order for your speakers to work. The amp is under the center console and powers all the speakers as well as the sub. If I were you, I'd bypass that entire Bose setup and get some component speakers for the front and regular coax in the rest of the vehicle, all powered by it's own amp. Then, another amp powering just the sub you add.

so... if you were me.. which harness would you use??

If your not worried about the chime don't use a harness and do a total rewire as you will have to find an optional acc wire to turn the head unit on and off with the key. It is possible to wire around the bose amp but just as easy to shoot new wires to the doors and rear. The 03 is pretty easy with lots of room for wire.

so you say just run a new set of -/+ wires to the accessory panel and get my power from there? and just totally foret about the factory harness altogether?

i found a wire pinout of my truck. Im gonna just tap into those 3 wires. All i need is constant/switched power and neg. It may not be as easy as pluggin in a connector, but for a few extra minutes of work im saving like 50 bucks..

If anyone knows any reason as to why i shouldnt do this please speak up..

No switched wire at the factory harness
You will need to find switched under the dash or at the fuse panel.

No switched wire? I thought there was a constant, ignition, and ground in there???

Maybe the graphic I saw was wrong. Do you have or know the pinout?

Try using a test light to find what you need.