Thread: 2004 Montana/Sunfire --> 2003 GP GT

So a long while back I had a side project to install a stereo from an 04 Sunfire (it's the same stereo that's in the Montana) in my 03 Grand Prix GT. I have most of the wires figured out thanks to the Montana and Grand Prix diagrams in Crutchfield's knowledge base. The issue is that the new stereo doesn't have a traditional switched power (accessory), but instead turns on via the data line in pin #1. Can I just wire the ACC wire from the 03 GP side of the harness to the data line on the Sunfire side of the harness to get switched power?

*EDIT*
HERE is the diagram for the 04 Grand Prix (which uses the same harness as the Montana) and it seems to be more intuitive, but I still run into the switched power issue.

NO!

I don't believe that the 97-03 Grand Prix's can do radio turn-on over data. If you run switched power into the new radio's Data line, you will probably fry the radio.

If it was me, I wouldn't even try. If your dead set on trying to make this work, at the risk of frying your electrical system, I'd tap the data input of the new radio into the data bus of your car. Chances are very good that it's not going to work, and may very well cause major problems, but that's your best bet in trying it (Again, at EXTREME risk to your electronics)

-Rob

Ah, after some more research I follow you. Guess I'll use that radio as donor parts for soldering new face buttons in my 03's stereo.