LittleNo

i have a 2004 Sierra 2500 HD with the basic radio (without onstar). i want to install a aftermarket radio. Now i have the wiring diagrams of a 2002 model, are they similar to the 2004?

the main question is: will i get any problems if i remove the stock radio? There's one wire called "serial data" which is connected to the computer data lines of the vehicle, maybe i get into trouble if this is removed? if so, what do i need to install a aftermarket radio without problems?

xts392

I do car audio for a living. there is difference between the 02 and 04. there is a data harness that puts the factory radio somewhere else. No one really knows what the factory radio keeps. You dont have to use the data harness but is recamended. I have done it both ways and not had any problems.

anotherwagner

Easiest way go to walmart buy the gm harness and use it. that way if ou every get rid of the truck it's easy to stick the factory radio back in and keep your new head unit.

Gadnorph

Go to crutchfield.com. I bought all of my stuff there and installed it myself. They give you everything you need from instructions to all wiring adapters. They have great tech support too. Pretty decent prices too if you catch them on sale.