How do u set up the aux in a 2002 chevy avalanch?

-i have a chevy avalanch its a 2002 i notic3d a aux button on the stock sterio im woundering how you hook something up so that the aux works for an mp3More than likely there is an auxilary input on the rear of the stock headunit (not a typical minijack input, but a proprietary multi-pin input). Assuming that is the case, you should be able to purchase an adapter online or through the dealership that would convert that port into either a minijack input or rca inputs.
Go to www.usaspec.com, input your vehicle information and select for an aux adapter. I would suggest getting an ipod adapter with aux input in it. I've done plenty of them and its the best way and simple direct plug and play. Good luck.