2003 I think was the year they switched to the radios that they used in the Suburbans (6 changer)

Now that's a Double Din unit so it opens you up to a handful of good options for radio replacement. Especially if you want navigation.

You could also look at a new OEM unit if that's the route you'd like. Do a bit of Googling to find what you like

 

I wonder how many Blazers were made with a 6 cd changer option. When I bought the vehicle in 2006, the window sticker just said cd player. When I took it home, I got out the manual to see how to operate the the player, i first opened the book to where the cd player was and the picture in the manual did not match up to what I had. Oh, I thought, the dealer stuck some other unit in. So I looked around and opened it up to where the 6 cd changer section was and to my surprise the picture match up.

tenorsaxdude, you are probably right, I think they change the stereo for the 2003 year. However, according to manual, the single CD player was an option. It looks like the 6 CD changer option would have been the highest option for that year. I don't know anything about the aftermarket stereos and just trying to learn. Thanks for that info. If my opening is a Double DIN, then why would I needed an adaptor?

 

Is the Aux. button on the stereo for plugging additional items in? Where would there be a place to plug things into the stereo?

 

Looking at your unit again, its the exact same unit that we had in our 2003 Chevy Z71 Suburban

Your unit is double din so if you are going to put another double din in place, you will only need the mounting hardware for that specific double din unit (and/or the GM faceplate/bracket)

If you want to go smaller (1 or 1.5 din) you will be looking at getting adapters (aka plastic plates to fill the gap). Biggest thing first is to figure out what you want to replace it with, then work from that point. For me I went from a 1.5 din to a double din because I knew the cars had the double dins out there, and I wanted touch screen nav

Unless there is a port on the unit's face (which I don't believe there is) it is a spare button. If you had a tape player it would have used that button to select that as the input section

 

Just replaced my OEM unit with a Pioneer from Best Buy. Took the guy about 10 minutes to remove and install the new unit. While they in there, had them replaced the door speakers too. Total cost was about $300.


My BB had everything they needed i.e. wiring harness, adapter plate, etc.